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  • Polymer and Materials Science  (21,194)
  • Cell & Developmental Biology  (6,449)
  • ddc:330
  • Deutschland
  • 1990-1994  (27,674)
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  • 1
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    Berlin : Duncker & Humblot | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2016-04-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 2
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2014-08-15
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 3
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2014-08-15
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 4
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    Marburg : Metropolis-Verl. | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2016-04-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 5
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2016-04-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 6
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    Ulm : Univ.-Verl. Ulm | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2016-04-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 7
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    Heidelberg : Physica-Verl. | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2016-04-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 8
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2016-04-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 9
    Publication Date: 2018-04-30
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 10
    Publication Date: 2018-04-30
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 11
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2014-08-15
    Keywords: ddc:330
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    Language: German
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  • 12
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2016-04-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 13
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    Berlin : Birkhäuser | Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2018-11-19
    Description: Wir haben zwanzig Jahre Umweltpolitik betrieben, haben nach Nanogrammen von Giften gejagt und Schadstoffemissionen reduziert. Vielleicht ist die Umwelt dadurch etwas sauberer geworden, aber dennoch drohen unserer Ökosphäre immer größere Katastrophen. Was machen wir falsch? Jeder Verbrauch, sei es von Rohstoffen, sei es von Energie, zieht unweigerlich ein Stück veränderte Umwelt nach sich. Und wir verbrauchen Megatonnen. Friedrich Schmidt-Bleek hat ein ökologisches Maß entwickelt, das erstmals den Verbrauch umfassend bestimmen kann. Dieses Maß - MIPS für Material Intensität Pro Serviceeinheit - ermöglicht es, die Umweltbelastung von Prozessen, Produkten und Leistungen zu ermitteln und miteinander zu vergleichen. Wollen wir dauerhaft unsere Ökosphäre retten, müssen wir in recht kurzer Zeit dass Ziel "Faktor 10" erreichen: also Reduzierung allen Verbrauchs auf den zehnten Teil - bei gleichbleibendem Wohlstand. Der Autor zeigt praxisnahe Wege, an dieses Ziel zu gelangen. Wir müssen nicht einfach den Gürtel enger schnallen, sondern wir müssen lernen, mit den zur Verfügung stehenden Ressourcen rationaler und effektiver umzugehen. Es ist durchaus üblich, Wohlstand zu schaffen - für alle Menschen.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 14
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 27 (1994), S. 133-149 
    ISSN: 0886-1544
    Keywords: MAP4 depletion ; antibody blocking ; detyrosination ; midbody ; asymmetric cell processes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous immunolocalization studies using many primate cultured cell lines demonstrated that a microtubule-associated protein of Mr ∼210,000 which is now called MAP4, is present along the length of microtubules in interphase and mitotic cells [Bulinski and Borisy (1980) J. Cell Biol. 87:802-808; DeBrabander et al. (1981) J. Cell Biol. 91:438-455]. Since MAP4 has been implicated as a microtubule stabilizer, we asked whether all classes of microtubules possess an equal complement of MAP4. We have reexamined the cellular distribution of MAP4, using both conventional double-label immunofluorescence and an antibody blocking technique [Schulze and Kirschner (1987) J. Cell Biol. 104:277-288] to highlight microtubules lacking, or depleted in, MAP4. These techniques have revealed that thin processes extending from monkey kidney cells (TC-7), and those made by human neuroblastoma cells (IMR-32) in response to retinoic acid, are often deficient in MAP4 immunoreactivity. Since both types of cellular processes contain stable microtubules, which are enriched in detyrosinated (Glu) tubulin, we tested the ability of MAP4 to bind to microtubules made from pure Glu and pure tyrosinated (Tyr) tubulin in vitro. MAP4 bound to both types of microtubules, and the similar saturation level of MAP4 binding to Glu and Tyr microtubules suggested that differential binding to these forms of tubulin does not contribute directly to a mechanism for segregation of MAP4 on microtubules in vivo. In TC-7 cells, we also observed MAP4-depletion on single microtubules, distal regions of broad cytoplasmic extensions, and midbodies of dividing cells. MAP4 depletion may reflect recent, rapid growth of microtubules to which MAP4 has not yet bound, or the presence of other MAPs that may compete with MAP4 for binding sites on the MT. We suggest that different levels of MAP4 on microtubules may directly modulate microtubule dynamics within single cells, as well as other microtubule functions such as those involving microtubule motor activity. © 1994 Wiley-Liss, Inc.
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  • 15
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 27 (1994), S. 193-205 
    ISSN: 0886-1544
    Keywords: amoeboid motility ; fluorescence ratio imaging ; BCECF ; nematodes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The development and locomotion of the amoeboid sperm of the nematode, Ascaris suum, depend on precise control of the assembly of their unique major sperm protein (MSP) filament system. We used fluorescence ratio imaging of cells loaded with BCECF to show that intracellular pH (pHi) is involved in controlling MSP polymerization in vivo. Spermatogenesis is marked by a cycle of MSP assembly-disassembly-reassembly that coincides with changes in pHi. In spermatocytes, which contain MSP in paracrystalline fibrous bodies, pHi was 6.8, 0.6 units higher than in spermatids, which disassemble the fibrous bodies and contain no assemblies of MSP filaments. Activation of spermatids to complete development resulted in rapid increase in pHi to 6.4 and reappearance of filaments. Treatment of spermatocytes with weak acids caused the fibrous bodies to disassemble whereas incubation of spermatids in weak bases induced MSP assembly. The MSP filaments in spermatozoa are organized into fiber complexes that flow continuously rearward from the leading edge of the pseudopod. These cells established a pseudopodial pH gradient with pHi 0.15 units higher at the leading edge, where fiber complexes assemble, than at the base of the pseudopod, where disassembly occurs. Acidification of these cells caused the MSP cytoskeleton to disassemble and abolished the pH gradient. Acid removal resulted in reassembly of the cytoskeleton, re-establishment of the pH gradient, and re-initiation of motility. MSP assembly in sperm undergoing normal development and motility and in cells responding to chemical manipulation of pHi occurs preferentially at membranes. Thus, we propose that filament assembly in sperm is controlled by pH-sensitive MSP-membrane interaction. © 1994 Wiley-Liss, Inc.
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  • 16
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 27 (1994), S. 248-261 
    ISSN: 0886-1544
    Keywords: myogenesis ; protein isoforms ; muscle types ; Z-disc ; phosphorylation ; chicken muscle ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphogenesis of functional myofibrils in chick skeletal and cardiac muscle occurs in greatly different time spans, in about 7 and 2 days, respectively. In chick skeletal myogenic cells, one isoform of the 250 kD actin-binding protein (ABP) filamin is associated with stress fiber-like structures of myoblasts and early myotubes, then disappears for approximately 4 days, whereupon a second filamin isoform reappears at the Z-disc periphery. We sought to determine if cardiac myogenesis involves this sequence of appearance, disappearance, and reappearance of a new filamin isoform in a compressed time scale. It was known that in mature heart, filamin is localized at the Z-disc periphery as in mature (fast) skeletal muscle, and is also associated with intercalated discs. We find that myocardial filamin has an apparent molecular weight similar to that of adult skeletal muscle filamin and lower than that of smooth muscle filamin, and that both skeletal and cardiac muscle contain roughly 200 filamin monomers per sarcomere. Two-dimensional peptide mapping shows that myocardial filamin is very similar to skeletal muscle filamin. Myocardial, slow skeletal, and fast skeletal muscle filamins are all phosphorylated, as previously shown for filamin of non-striated muscle. Using immunofluorescence, we found that filamin could not be detected in the developing heart until the 14-somite stage, when functional myofibrils exist and the heart has been beating for 3 to 4 hours. We conclude that in cardiac and skeletal myogenesis, different sequences of filamin gene expression result in myofibrils with similar filamin distributions and isoforms. © 1994 Wiley-Liss, Inc.
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  • 17
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 27 (1994), S. 272-283 
    ISSN: 0886-1544
    Keywords: cell cycle ; transcription ; mRNA decay ; autoregulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The single alpha-tubulin gene of Tetrahymena thermophila was isolated from a genomic library and shown to encode a single protein. Comparisons of the rates of evolution of this gene with other alpha-tubulin sequences revealed that it belongs to a group of more evolutionarily constrained alpha-tubulin proteins in animals, plants, and protozoans versus the group of more rapidly evolving fungal and variant animal alpha-tubulins. The single alpha-tubulin of Tetrahymena must be used in a variety of microtubule structures, and we suggest that equivalently conserved alpha-tubulins in other organisms are evolutionarily constrained because they, too, are multifunctional. Reduced constraints on fungal tubulins are consistent with their simpler microtubule systems. The animal variant alpha-tubulins may also have diverged because of fewer functional requirements or they could be examples of specialized tubulins. To analyze the role of tubulin gene expression in regulation of the complex microtubule system of Tetrahymena, alpha-tubulin mRNA amounts were examined in a number of cell states. Message levels increased in growing versus starved cells and also during early stages of conjugation. These changes were correlated with increases in transcription rates. Additionally, alpha-tubulin mRNA levels oscillate in a cell cycle dependent fashion caused by changes in both transcription and decay rates. Therefore, as in other organisms, Tetrahymena adjusts alpha-tubulin message amounts via message decay. However the complex control of alpha-tubulin mRNA during the Tetrahymena life cycle involves regulation of both decay and transcription rates. © 1994 Wiley-Liss, Inc.
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  • 18
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 28 (1994), S. 45-58 
    ISSN: 0886-1544
    Keywords: MTOC ; cytoplasmic microtubule complex ; antitubulin ; Immunofluorescence ; ultrastructure ; immunogold ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We investigated the microtubule (MT) cytoskeleton and microtubule centers (MTC) in undifferentiated amoebae by indirect immunofluorescence with six monoclonal antitubulin antibodies, and by transmission electron microscopy and immunogold ultracytochemistry. Interphase amoebae of both species contain a distinct cytoplasmic complex of MTs, which is more elaborate in Protostelium mycophaga. In Acytostelium leptosomum amoebae a single MTC is attached to each interphase nucleus at its pointed end, as in the other dictyostelid cellular slime molds Dictyostelium discoideum and Polysphondylium violaceum. Ultrastructurally, MTCs of A. leptosomum also resemble those of these two species: They consist of an electron-opaque core shaped like a stout rod, which is embedded, together with nodules, in a fuzzy matrix. The nodules are the points of origin of the MTs. In most amoebae of P. mycophaga there are two MTCs on opposite sides of and close to the nucleus, but many amoebae also contain a variable number of MTCs that are remote from the nucleus. Nucleus-associated and “remote” MTCs are structurally identical. They consist of a ring-shaped core with inner and outer diameters of ca. 130 nm and 340 nm. A plug sits in the ring, and satellites are connected to the core by fine fibrils. The satellites are the points of origin of MTs. New MTCs are apparently formed during mitosis, the parent MTC probably serving as a template for the genesis of a new ring. The results support the notion that phylogenetically related organisms have similarly constructed MTCs and that these are dissimilar in less closely related organisms. © 1994 Wiley-Liss, Inc.
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  • 19
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 28 (1994), S. 135-142 
    ISSN: 0886-1544
    Keywords: bidirectional swimming ; flagellar movement ; helical bends ; 9+0 axoneme ; planar bends ; viscosity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Spermatozoa of the small myzostomid worm Myzostomum cirriferum usually swim with the flagellum foremost but occasionally stop and then swim with the head foremost. The spermatozoa have axoneme of the 9+0 type; thus each lacks the central pair microtubules. The flagellum emerges in the anterior end of the cell body and attaches to it with junctions. To understand the mechanism regulating the swimming direction of the spermatozoa, we recorded the sperm and their flagellar movements using a video camera with a high-speed shutter. The effects of calcium and viscosity on these movements were also examined.The cell body with the flagellum attached to it formed a curved plate during beating, while the free portion of the flagellum beats with small helical bends. Motive force to propel a spermatozoon was mainly due to the bends in the cell body. The spermatozoa reversed the direction of their swimming as a result of a change in the direction of bend propagation. The direction of bend propagation was regulated by calcium; the bends in the cell body propagated from the end of the head toward the free portion of the flagellum at low concentrations of Ca2+, whereas the direction of bend propagation was reversed at high concentrations of this ion. High viscosity of the medium stimulated a change in the direction of bend propagation. © 1994 Wiley-Liss, Inc.
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  • 20
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 28 (1994), S. 155-164 
    ISSN: 0886-1544
    Keywords: microfilamentous cytoskeleton ; actin binding proteins ; formyl peptides ; ionic extraction ; immunoblots ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: F-actin is a major component of the neutrophil (PMN) cytoskeleton. In basal PMNs, F-actin exists in two structurally and functionally distinct pools: Triton insoluble F-actin (TIF)-cold insensitive, not depolymerizable by dilution, and distributed in pseudopods and submembranous locations; and Triton soluble F-actin (TSF)-unstable in cold, diffusely distributed, and gelsolin enriched. The element(s) conferring these unique properties to the Triton insoluble F-actin pool are unknown, but logically include distinct actin regulatory proteins. To study the morphologic and functional determinants of the Triton insoluble F-actin pool, the distribution and quantity of three candidate regulatory proteins, α-actinin, tropomyosin (TM), and actin binding protein (ABP-280), were compared in F-actin (Triton insoluble and Triton soluble) and G-actin pools isolated from basal and chemotactic factor activated human PMNs in suspension, using immunoblots and ionic extraction. F-actin content was measured by NBDphallacidin binding and gel scans. The results show that: (1) α-actinin, actin binding protein 280, and tropomyosin are localized to TIF and excluded from TSF; (2) TM, α-actinin, and ABP 280 are required to stabilize fractions of Triton insoluble F-actin in PMNs; and (3) chemotactic factor activation results in release of a fraction of TM from the Triton insoluble F-actin pool in temporal association with F-actin polymerization in the Triton insoluble F-actin pool. Shifts in ABP 280 or α-actinin do not occur. The results suggest that TM, α-actinin, and ABP 280 provide structure to TIF and that TM release from TIF is involved in chemotactic factor induced actin polymerization in PMNs. © 1994 Wiley-Liss, Inc.
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  • 21
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 28 (1994), S. 165-178 
    ISSN: 0886-1544
    Keywords: WISH ; Keratin ; 3-D reconstruction ; mitosis ; intermediate filaments ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Three dimensional (3-D) reconstruction of four mitotic WISH cells from ultrathin sections gave an informative representation of the spatial distribution of keratin densities in these cells. The correspondence between the densities as studied by transmission electron microscopy (TEM) and the Keratin bodies initially revealed by immunoflourescent colabeling of cultures, was confirmed by immunoelectron-microscopy. The smaller, and sometimes more elongated densities, were relatively abundant just beneath the subplasmalemmal microfilament band; and at certain levels of the mitotic cell they were observed to be connected to neighboring densities by intact intermediate filaments (IFs). The larger and more spherical densities appeared to be somewhat more discrete and randomly distributed. Other observed associations of the keratin densities included the telophase contractile ring of microfilaments, chromosomes, the reformed telophase nucleus, and desmosomal junctions with neighboring interphase cells. Cytochalasin D (CD) treatment of cells displaced the peripheral keratin densities toward the cell membrane. The density volume constituted 0.52% to 1.57% of the total cell volume, and the proportional density size was decreased in the cells that had progressed into anaphase and telophase. The observed formation and subsequent dissolution of keratin densities during mitosis may represent a dynamic mechanism of restructuring the keratin cytoskeleton in an unpolymerized form in order to allow for rapid reformation of interphase cell junctions. The physical associations observed between intact IFs and the keratin densities may provide support at certain depths of the mitotic cell, and the juxtaposition of densities with nuclear components suggests a possible source of and role for keratin IFs during nuclear events. © 1994 Wiley-Liss, Inc.
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  • 22
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 28 (1994), S. 199-204 
    ISSN: 0886-1544
    Keywords: axoneme ; cilia ; flagella ; microtubule ; motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Observations that were interpreted to provide evidence for equivalent functions of all axonemal dyneins should be reinterpreted, and models based on this assumption should be abandoned. In the future, attempts to understand the mechanisms for flagellar bending, oscillation, and bend propagation should start from the assumption that each type of axonemal dynein may have a specific function. At least three distinct functions can now be identified: bend initiation, maintenance of the angle of propagating bends, and generation of power to overcome viscous resistances. Only the last of these three functions is an outer arm dynein function. © 1994 Wiley-Liss, Inc.
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  • 23
    ISSN: 0886-1544
    Keywords: cytoskeleton ; actin binding ; transgelin sequence ; gelation ; gene family ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have used degenerate oligonucleotides, derived from the amino acid sequence of transgelin peptides [Shapland et al., 1993: J. Cell Biol. 121:1065-1073], to isolate and sequence overlapping cDNA clones encoding this actin gelling protein. Primers with 5′ restriction enzyme sites directed against the N and C terminal amino acids present in these clones were then used to amplify and clone the entire transgelin coding region from reverse transcribed rat small intestine cDNA (RT-PCR). These studies have shown that transgelin is the product of a single gene which is conserved between yeast, Drosophila, molluscs, and humans. Transgelin is expressed as a single message that is regulated at the level of transcription in SV40 transformed 3T3 cells. Our data have shown that transgelin and several other proteins of unknown function, SM22α [Pearlstone et al., 1987: J. Biol. Chem. 262:5985-5991], mouse p27 [Almendral et al., 1989: Exp. Cell Res. 181:518-530], and human WS3-10 [Thweatt et al., 1992: Biochem. Biophys. Res. Commun. 187:1-7], share extensive homology. More limited regions of homology shared between transgelin and other proteins such as rat NP25 (unpublished), chicken calponins α and β [Takahashi and Nadal-Ginard, 1991: J. Biol. Chem. 266:13284-13288], and Drosophila mp20 [Ayme-Southgate et al., 1989: J. Cell Biol. 108:521-531] suggest that all of these proteins may be classified as members of a new transgelin multigene family. © 1994 Wiley-Liss, Inc.
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  • 24
    Electronic Resource
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    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 28 (1994), S. 279-284 
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 25
    ISSN: 0886-1544
    Keywords: cytoskeleton ; cell culture ; gene expression ; Northern blot ; serum-induction ; rat ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cytochalasin D and dBcAMP cause cultured astrocytes to change from flat cells to retrated process-bearing cells. F-actin was present throughout cells stimulated with dBcAMP for 16 h, whereas cytochalasin D caused F-actin to form massive aggregates at the tips of the cell processes. The two drugs differently regulated the expression of both β-actin and tropomyosin genes in astrocytes cultured in the presence or absence of serum: dBcAMP caused down-regulation and cytochalasin D caused up-regulation. Northern blot analyses indicated that: (1) serum deprivation halved the concentration of all tropomyosin transcripts (TM-1, TM-2, TM-4, TMBr-1, TMBr-2). Serum induced TM-4 via transcriptional activation, independent of protein synthesis, (2) dBcAMP induced down-regulation of β-actin (-50%) and tropomyosin transcripts (-35 to 52%) even in the presence of serum. The concentration of profilin mRNA decreased in dBcAMP-reactive astrocytes (-46%). The decrease in β-actin mRNA concentration was not blocked by cycloheximide, whereas down-regulation of tropomyosin transcripts was completely reversed when protein synthesis was inhibited, and (3) cytochalasin D induced an increase in the concentration of tropomyosin transcripts (+ 69 to 185%) which was cumulative with serum stimulation. Cytochalasin D induction of both β-actin and TM-4 operated through transcriptional activation, independent of protein synthesis.The production of all tropomyosin transcripts examined here were strictly coordinated with β-actin expression in serum-, dBcAMP- and cytochalasin D-treated astrocytes. This indicates that the differential expression of tropomyosin isoforms occurring during astrocyte maturation is due to more complex regulation than that involved in serum- or cAMP-stimulated astrocytes. © 1994 Wiley-Liss, Inc.
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  • 26
    Electronic Resource
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    Cell Motility and the Cytoskeleton 28 (1994), S. 333-345 
    ISSN: 0886-1544
    Keywords: ciliary beat frequency ; metachronal wave ; ciliary coupling ; extracellular ATP ; acetylcholine ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the present work we measured in real time the metachronism and degree of correlation between beating cilia from cultured mucociliary epithelium. The method is based on simultaneous measurement of ciliary beat frequency, phase shifts, and correlation factors in two directions: parallel and perpendicular to the effective stroke direction (ESD). From the phase shifts the lengths of wave components, and consequently the metachronal wavelength and direction, were evaluated.On active ciliary areas of cultured frog esophagus under normal conditions, a relatively high degree of correlation is observed, but cilia are more correlated in direction parallel to ESD which is also the direction of the mucus propulsion. The length of the wave component parallel to ESD is more than twice as large as that of the perpendicular component. The metachronal wavelength was found to be in the range of 5-9 μm, and the direction of the wave propagation was in the range of 90°-125° clockwise to the ESD.When ciliary beat frequency was rapidly increased by extracellular ATP or acetylcholine, only minor effects were observed on the degree of correlation between beating cilia. The length of the wave component parallel to ESD showed the most dramatic effect increasing up to tenfold. The perpendicular to ESD component was not affected by the stimulation. Consequently, the metachronism became more laeoplectic with the angle between the ESD and the wave directions decreasing by 10°-30°, and the metachronal wavelength remained unaltered. © 1994 Wiley-Liss, Inc.
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    Cell Motility and the Cytoskeleton 29 (1994), S. 57-71 
    ISSN: 0886-1544
    Keywords: microtubule bundling ; cytoskeleton ; tau ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Microtubule protein extracted from dogfish erythrocyte cytoskeletons by disassembly of marginal bands at low temperature formed linear microtubule (MT) bundles upon reassembly at 22°C. The bundles, which were readily visible by video-enhanced phase contrast or DIC microscopy, increased in length and thickness with time. At steady state after 1 hour, most bundles were 6-11 μm in length and 2-5 MTs in thickness. No inter-MT cross-bridges were visible by negative staining. The bundles exhibited mechanical stability in flow as well as flexibility, in this respect resembling native marginal bands. As analyzed by SDS-PAGE and immunoblotting, our standard extraction conditions yielded MT protein preparations and bundles containing tau protein but not high molecular weight MAPs such as MAP-2 or syncolin. In addition, late fractions of MT protein obtained by gel filtration were devoid of high molecular weight proteins but still produced MT bundles. The marginal band tau was salt-extractable and heat-stable, bound antibodies to mammalian brain tau, and formed aggregates upon desalting. Antibodies to tau blocked MT assembly, but both assembly and bundling occurred in the presence of antibodies to actin or syncolin. The MTs were “unbundled” by subtilisin or by high salt (0.5-1 M KCl or NaCl), consistent with tau involvement in bundling. High salt extracts retained bundling activity, and salt-induced unbundling was reversible with desalting. However, reversibility was observed only after salt-induced MT disassembly had occurred. Reconstitution experiments showed that addition of marginal band tau to preassembled MTs did not produce bundles, whereas tau presence during MT reassembly did yield bundles. Thus, in this system, tau appears to play a role in both MT assembly and bundling, serving in the latter function as a coassembly factor. © 1994 Wiley-Liss, Inc.
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    Cell Motility and the Cytoskeleton 29 (1994), S. 82-93 
    ISSN: 0886-1544
    Keywords: trichomonads ; cytoskeleton ; antibodies ; electrophoresis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The production of monoclonal antibodies and the use of biochemical techniques revealed that B-type costa proteins in trichomonads are composed of several major polypeptides with molecular weight detected between 100 and 135 kDa similar to those found in the A-type costae. Although differences were observed between the two types in their fine structure, we tested whether proteins composing the two costa types belong to the same protein family. A polyclonal antibody produced against the 118 kDa costa protein of Trichomonas vaginalis also recognized a 118 kDa costa protein in all other trichomonad genera studied so far whether they have A- or B-type costae. Moreover biochemical characteristics of costa proteins indicated that these proteins might represent a novel class of striated root-forming proteins in addition to centrin, giardin, and assemblin. © 1994 Wiley-Liss, Inc.
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    Cell Motility and the Cytoskeleton 29 (1994), S. 110-116 
    ISSN: 0886-1544
    Keywords: high-molecular weight MAPs ; microfilaments ; microtubules ; low-shear viscometry ; taxol ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: High molecular weight microtubule-associated proteins MAP1A and MAP2 form thin projections from microtubule surfaces and have been implicated in crosslinking microtubules and other cytoskeletal components. We have purified native MAP1A from bovine brain and have studied its interaction with G- and F-actin. Using a solid-phase immunoassay we show that MAP1A binds in a dose-dependent manner to both G-actin and F-actin. Addition of MAP1A to F-actin causes gelation of F-actin and SDS-PAGE analysis shows that MAP1A co-sediments with the gelled network, under conditions where F-actin alone does not pellet. The low apparent viscosity of F-actin is markedly increased in the presence of MAP1A, suggesting that MAP1A can crosslink F-actin. Co-incubation experiments indicate that MAP1A and MAP2 may bind to common or overlapping sites on the actin molecule. The widespread distribution of MAP1A and its interaction with microtubules, actin, and intermediate filaments suggests that it may constitute an important determinant of neuronal and non-neuronal cellular morphology. © 1994 Wiley-Liss, Inc.
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    Cell Motility and the Cytoskeleton 29 (1994), S. 141-154 
    ISSN: 0886-1544
    Keywords: dynein arms ; nexin links ; radial spokes ; relaxation oscillator ; doublet microtubules ; biological oscillators ; computer model ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Ciliary and flagellar motion is driven by the dynein-tubulin interaction between adjacent doublets of the axoneme, and the resulting sliding displacements are converted into axonemal bends that are propagated. When the axoneme is bent in the normal beating plane, force develops across the axoneme in the plane of the bend. This transverse force (t-force) has maximal effect on the interdoublet spacing of outer doublets 2-4 on one side of the axoneme and doublets 7-9 on the opposite side. Episodes of sliding originates as the t-force brings these doublets into closer proximity (allowing dynein bridges to form) and are terminated when these doublets are separated from each other by the t-force. A second factor, the adhesive force of the dynein-tubulin attachments (bridges), also acts to pull neighboring doublets closer together. This force resists termination of a sliding episode once initiated, and acts locally to give the population of dynein bridges a type of excitability. In other words, as bridges form, the probability of nearby bridges attaching is increased by a positive feedback exerted through the interdoublet spacing. A conceptual working hypothesis explaining the behavior of cilia and flagella is proposed based on the above concepts. Additionally, the feasibility of this proposed mechanism is demonstrated using a computer simulation. The simulation uses a Monte Carlo-type algorithm for dynein attachment and adhesive force, together with a geometric evaluation of the t-force on the key microtubule pairs. This model successfully develops spontaneous oscillations from any starting configuration (including a straight position). It is compatible with the physical dimensions, mechanical properties and bridge forces measured in real cilia and flagella. In operation, it exhibits many of the observed actions of cilia and flagella, most notably wave propagation and the ability to produce both cilia-like and flagella-like waveforms. © 1994 Wiley-Liss, Inc.
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    Cell Motility and the Cytoskeleton 29 (1994), S. 195-203 
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    Cell Motility and the Cytoskeleton 29 (1994), S. 339-344 
    ISSN: 0886-1544
    Keywords: microfilament ; phalloidin ; immunoblotting ; immunocytochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Anti-actin monoclonal antibodies were prepared using phalloidin-stabilized actin that was purified from pea roots by DNase I affinity chromatography. One monoclonal antibody, designated mAb3H11, bound plant actin in preliminary screenings and was further analyzed. Immunoblot analysis showed that this antibody had a high affinity for plant actin in crude and purified preparations but a low affinity for rabbit muscle actin. In immunoblots of plant extracts separated on two-dimensional gels it appeared to bind all actin isoforms recognized by the JLA20 anti-chicken actin antibody. Using immunofluorescent cytochemistry, the antibody was used to observe actin filaments in aldehyde-fixed and methanol-treated tobacco protoplasts. These results indicate that mAb3H11 should be a useful reagent for the study of plant actins. © 1994 Wiley-Liss, Inc.
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    Cell Motility and the Cytoskeleton 29 (1994), S. 366-374 
    ISSN: 0886-1544
    Keywords: cytoskeleton ; microfilaments ; cytochalasin ; gravity ; amiprophos-methyl ; tip-growth ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Apical cells of protonemata of the moss Ceratodon purpureus are unusual among plant cells with sedimentation in that only some amyloplasts sediment and these do not fall completely to the bottom of vertical cells. To determine whether the cytoskeleton restricts plastid sedimentation, the effects of amiprophos-methyl (APM) and cytochalasin D (CD) on plastid position were quantified. APM treatments of 30-60 min increased the plastid sedimentation that is normally seen along the length of untreated or control cells. Longer APM treatments often resulted in more dramatic plastid sedimentation, and in some cases almost all plastids sedimented to the lowermost point in the cell. In contrast, the microfilament inhibitor CD did not affect longitudinal plastid sedimentation compared to untreated cells, although it did disturb or eliminate plastid zonation in the tip. These data suggest that microtubules restrict the sedimentation of plastids along the length of the cell and that microtubules are load-bearing for all the plastids in the apical cell. This demonstrates the importance of the cytoskeleton in maintaining organelle position and cell organization against the force of gravity. © 1994 Wiley-Liss, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 113-120 
    ISSN: 0887-624X
    Keywords: polyurethane ; chromatography ; stoichiometry ; GPC ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of formation of polyurethane prepolymers is studied by an analytical technique which involves reactive quenching of the isocyanate, separation of the oligomeric species by GPC, and measurement by UV absorbance of the quenched moieties. The precision of the kinetic parameters and the ratios of the oligomers are determined. The effect of changes in reactant stoichiometry on the ratio of oligomers is measured and compared to the value predicted by an equation from Flory. Toluene diisocyanate is shown to give fewer high oligomers than predicted, while methylene diphenylene diisocyanate gives nearly the predicted values. Tetramethylxylene diisocyanate gives more high oligomers than predicted, an unexpected but possibly important result. Catalyst is shown to increase the reaction rate of the last by more than 200 times. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 159-165 
    ISSN: 0887-624X
    Keywords: 4-hydroxybenzoic acid ; 6-thioxantone-2-carboxylic acid ; copolyesters ; whiskers ; polycondensation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 6-Hydroxythioxanthone-2-carboxylic acid (HTCA) was prepared from commercial dimethylnitroterephthalate via 2-(4'-hydroxythiophenyl) terephthalic acid. HTCA was acetylated and polycondensed in an inert reaction medium at 350 or 400°C. An insoluble and infusible, highly crystalline polyester was obtained, which did not form whisker-like crystals. Furthermore, copolyesters with 4-hydroxybenzoic acid (4-HBA) were synthesized and whiskers were obtained at a molar ratio of 1 : 9 (in favor of 4-HBA). A meltable, nematic copolyester was prepared by cocondensation of silylated 6-acetoxythioxanthone-2-carboxylic acid and silylated 4-acetoxybenzoic acid in bulk. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 167-174 
    ISSN: 0887-624X
    Keywords: polyimide molecular composite ; crosslinking ; internal acetylene ; laminate processing ; high modulus ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyimide/polyimide molecular composite (MC) films comprised of a rigid polyimide derived from biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) and a flexible polyimide derived from BPDA and bis (3,3'-diaminodiphenyl) acetylene (intA) and/or oxydianiline (ODA) were prepared by blending the polyamic acid solutions in 7 : 3 weight ratio, and then imidizing the blend films. Acetylene content in the flexible polyimide backbone was controlled by the ratio of intA and ODA. Cold-drawing of the blend polyamic acid films, followed by imidization, gives high modulus polyimide/polyimide MC films. The modulus of the MC films increased almost linearly with the draw ratio, reaching 25.5 GPa for the 40% drawn film. Acetylene groups in the flexible polyimide can be thermally cured to crosslink. The onset of exotherm appeared at 340°C on DSC, reaching maximum at 398°C. After the thermal crosslinking, the MC films maintained the high modulus, though elongation became small. Taking advantage of the crosslinkable acetylene units, two MC films were laminated and processed at 400°C for 20 min under 100 kg/cm2 to give a good-quality laminate film. The interface of the two films was strongly bonded through the crosslinking of acetylene groups. Laminate films maintained the high modulus afforded by the cold-drawing. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 355-362 
    ISSN: 0887-624X
    Keywords: bisaryloxyencephthalic Acids ; polyaramides ; rigid-rod polymers ; molecular blends ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several 2,5-bisaryloxyterephthalic acids were prepared by a new method, namely arylation of diethyl-2,5-bistrimethylsiloxyterephthalate. Rigid-rod polyaramides were prepared by polycondensation of silylated diamines with a terephthaloylchloride with two diphenylsulfone side chains. Another polyamide was prepared from 2,5-bis(4′-cyanophenoxy) terephthalic acid and 1,4-diaminobenzene. None of these polyaramides is meltable and their solubilities differ largely. A copolymer of 1,4-diaminobenzene and 3,3′-dimethoxybenzidine is soluble in various organic solvents including polar vinyl monomers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 149-158 
    ISSN: 0887-624X
    Keywords: metallocene ; stereoselective catalyst ; propylene polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new silolene-bridged compound, racemic (1,4-butanediyl) silylene-bis (1-η5-in-denyl) dichlorozirconium (1) was synthesized by reacting ZrCl4 with C4H8Si (IndLi)2 in THF. 1 was reacted with trialkylaluminum and then with triphenylcarbenium tetrakis (penta-fluorophenyl) borate (2) to produce in situ the zirconocenium ion (1+). This “constraint geometry” catalyst is exceedingly stereoselective for propylene polymerization at low temperature (Tp = -55°C), producing refluxing n-heptane insoluble isotactic poly(propylene) (i-PP) with a yield of 99.4%, Tm = 164.3°C, δHf = 20.22 cal/g and M̄w = 350 000. It has catalytic activities of 107-108 g PP/(mol Zr · [C3H6] · h) in propylene polymerization at the Tp ranging from -55°C to 70°C, and 108 polymer/(mol Zr · [monomer] · h) in ethylene polymerization. The stereospecificity of 1+ decreases gradually as Tp approaches 20°C. At higher temperatures the catalytic species rapidly loses stereochemical control. Under all experimental conditions 1+ is more stereospecific than the analogous cation derived from rac-dimethylsilylenebis (1-η5-indenyl)dichlorozirconium (4). The variations of polymerization activities in ethylene and in propylene for Tp from -55°C to +70°C indicates a Michaelis Mention kinetics. The zirconocenium-propylene π-complex has a larger insertion rate constant but lower thermal stability than the corresponding ethylene π-complex. This catalyst copolymerizes ethylene and propylene with reactivity ratios of comparable magnitude rE ˜ 4rp. Furthermore, rE.rp ˜ 0.5 indicating random copolymer formation. Both 1 and 4 activated with methylaluminoxane (MAO) exhibit much slower polymerization rates, and, under certain conditions, a lower stereo-selectivity than the corresponding 1+ or 4+ system. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 187-191 
    ISSN: 0887-624X
    Keywords: thermal degradation ; polysiloxane ; alternating copolymer ; thermal isomerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 219-227 
    ISSN: 0887-624X
    Keywords: Polyimidophosphonate ; dihydroxybismide ; phase transfer catalyst ; 31PNMR ; flame retardancy ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of dihydroxybisimide monomers and their subsequent polycondensation with dichlorophenylphosphine oxide by use of a phase-transfer catalyst are reported. The monomers were characterized by melting point, elemental analysis, and IR spectroscopy. The polyimidophosphonates were characterized by viscosity measurement, molecular weight determination, elemental analysis, IR, ESCA, 1H-NMR, 31P-NMR, and X-ray diffraction. Thermal stability and glass transition temperature (Tg) of the polymers were evaluated by TGA, DTA, and TMA. These polymers are self-extinguishing and readily soluble in highly polar solvents like DMF, DMSO, DMAC, NMP, HMPA, etc. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 605-630 
    ISSN: 0887-624X
    Keywords: free radical ; exit ; emulsion ; polymerization ; model ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The exit or desorption of free radicals from latex particles is an important kinetic process in an emulsion polymerization. This article unites a successful theory of radical absorption (i.e., initiator efficiency), based on propagation in the aqueous phase being the rate determining step for entry of charged free radicals, with a detailed model of radical desorption. The result is a kinetic scheme applicable to true “zero-one” systems (i.e., where entry of a radical into a latex particle already containing a radical results in instantaneous termination), which is still, with a number of generally applicable assumptions, relatively simple. Indeed, in many physically reasonable limits, the kinetic representation reduces to a single rate equation. Specific experimental techniques of particular significance and methods of analysis of kinetic data are detailed and discussed. A methodology for both assessing the applicability of the model and its more probable limits, via use of known rate coefficients and theoretical predictions, is outlined and then applied to the representative monomers, styrene and methyl methacrylate. A detailed application of the theory and illustration of the methodology of model discrimination via experiment is contained in the second article of this series. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 675-681 
    ISSN: 0887-624X
    Keywords: nickel ; coupling polymerization ; aromatic dichloride ; tert-butyl-substituted poly (ether ketone) ; de-tert-butylation ; Chemistry ; Polymer and Materials Science
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    Topics: Chemistry and Pharmacology
    Notes: tert-Butyl substituted poly (aryl ether ketone)s with relatively high molecular weights were prepared by the Ni-catalyzed polymerization of tert-butyl substituted aromatic dichlorides containing ether ketone unit. These polymers were amorphous and soluble in common organic solvents, such as THF, dichloromethane, and chloroform. De-tert-butylation of the polymer by the treatment of trifluoromethanesulfonic acid in the presence of toluene proceeded smoothly and produced crystalline poly (aryl ether ketone). © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 711-719 
    ISSN: 0887-624X
    Keywords: carbazolyl group ; liquid-crystalline polymer ; polyacrylate ; nematic phase ; smectic phase ; electron beam polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The new acrylate monomers 4-(ω-acryloyloxyalkyloxy)-N-(9-methyl-2-carbazolylmethylene) anilines containing from 2 to 11 methylenic units in their alkyl group and a carbazolyl group in the mesogenic unit were synthesized and polymerized by azobisisobutyronitrile (AIBN) as radical initiator and by low-energy electron beam (EB) initiation. The thermal properties of the resulting polymers were examined using differential scanning calorimetry and thermal optical polarizing microscopy. The polymer prepared by AIBN with a hexamethylene spacer exhibited a nematic phase from 73 to 170°C and with an undecamethylene spacer exhibited a smectic phase from 55 to 202°C. The isotropization temperature of the polyacrylates increased with increasing the number of carbons of the methylenic spacer. The yield of the resulting polymer was changed by EB irradiation temperature from 4.5 to 41%. The highest yield was obtained when the monomer was polymerized in a liquid-crystalline phase. The same tendency was observed in the molecular weight of the resulting polymers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 747-752 
    ISSN: 0887-624X
    Keywords: thermotropic copolyamides ; depression of transition temperatures ; p-aminobenzoic acid ; amide bond structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is proposed that depression of the transition temperatures, especially the melting point (Tm), can be achieved by the introduction of a different amide bond structure into the copolyamides of dicarboxylic acids and diamines by copolymerization of aminocarboxylic acids, such as p-aminobenzoic acid. The effect was examined by the amount and distribution of the structure in the copolylamindes. Copolycondensations of PEG3, p-aminobenzoic acid, and diamines with different chain lengths showed that the structural change of the amide bond in the copolymers, especially its distribution, was more important than its total amount in them. Several types of aminocarboxylic acids were briefly examined to study the effect. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 797-801 
    ISSN: 0887-624X
    Keywords: solid state photopolymerization ; exciton-phonon coupling ; homogeneous and heterogeneous reaction mechanism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photopolymerization reaction in di n-propyl ester of dicyano p-phenylene diacrylic acid crystal is shown to be mediated by exciton-phonon coupling. Raman phonon spectra suggest that at the initial stage of reaction progress, the reactant and the product form a solid solution. In the later stage, the reactant segregates out and forms its own lattice. The polymer lattice is shown to maintain a good degree of order. Infrared and Raman spectra confirm that the polymerization occurs by cyclobutane ring formation. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 829-840 
    ISSN: 0887-624X
    Keywords: chemical modification ; poly (epichlorohydrin) ; nadimide ; polyethers ; DSC ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chemical modification of poly(epichlorohydrin) (PECH) with nadimide derivatives using 1,8-diazabicyclo (5.4.0)-7 undecene to catalyze the substitution of the chlorine atom by acid compounds (DBU method) was accomplished. The linear polyethers obtained showed a degree of substitution from 5-80%, depending on time and temperature reaction. The Tg of modified polymers and Ea, calculated in the cure reactions, increases with substitution degree. Residual enthalpies were observed in all cases, which suggests that the curing reaction is incomplete. TGA measurements showed that the degradation has a greater dependence on the modification degree than on the introduced pendant group. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 869-877 
    ISSN: 0887-624X
    Keywords: polymer modification ; block copolymer ; hydroxylation of polyisoprene ; trifluoroacetylation of polyisoprene ; polymer monolayer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyisoprene (PIP) was found to react with trifluoroacetic acid (TFA) to give an adduct. Saponification of the ester gave a new alternating copolymer of ethylene and α-methyl vinyl alcohol. TFA did not react with polybutadiene (PBD) under these conditions, thus providing a way to produce amphiphilic block copolymers from PBD-b-PIP. TFA addition to the PIP block took place cleanly at an ambient temperature with 2 equiv of the acid in toluene to give block copolymer of PBD and trifluoroacetated PIP. This polymer is very soluble in toluene regardless of molecular weight. Methanolysis with NaOMe cleaved the ester to give PDB-b-(ethylene-alt-α-methyl vinyl alcohol) (PIPOH) in a MeOH/toluene mixture. Low molecular weight hydroxylated diblock copolymer is a viscous liquid when the ratio of PIP/PBD is 0.1 ( \documentclass{article}\pagestyle{empty}\begin{document}$\overline {M_n }$\end{document} = 4100, D = 1.3), but a solid with the ratio 0.5 (\documentclass{article}\pagestyle{empty}\begin{document}$\overline {M_n }$\end{document} = 7170, D = 1.6). High molecular weight polymer (\documentclass{article}\pagestyle{empty}\begin{document}$\overline {M_n }$\end{document} = 114,000, D = 1.4) with PIP/PBD ratio 0.1 is a hazy rubbery material. Block copolymers of PIPOH and poly(methacrylic acid) was also obtained from copolymers of PIP and poly(t-butyl methacrylate). The hydroxylated copolymers showed surface activity by monolayer formation on a Langmuir-Blodgett trough. The transfer of the monolayer on a silicon wafer gave z-type deposition, with the average ellipsometer thickness of the layer being about 40 Å thick per monolayer for \documentclass{article}\pagestyle{empty}\begin{document}$\overline {M_n }$\end{document} = 4100 copolymer. © 1994 John Wiley & Sons, Inc.
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  • 48
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 909-915 
    ISSN: 0887-624X
    Keywords: high-temperature polyarylates ; dihydroxytetraphenylethylene ; solubility behavior ; thermal behavior ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New polyarylates and aromatic polyethers were synthesized from 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene, and aromatic dicarboxylic acid chlorides and aromatic dihalides, respectively. The polyarylates having inherent viscosities of 0.28-1.05 dL/g were synthesized by either the two-phase method or the high-temperature solution method. All the polymers were easily soluble in N-methyl-2-pyrrolidone, N,N-dimethylformamide, pyridine, m-cresol, 1,4-dioxane, and 1,1,2,2-tetrachloroethane. They have glass transition temperatures in the range of 217-250°C and showed no weight loss below 315°C in both air and nitrogen atmospheres. Aromatic polyethers with inherent viscosities of 0.85-1.21 dL/g were obtained by the polycondensation of 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene and aromatic difluorides in the presence of potassium carbonate. These polymers having glass transion temperatures of 193-220°C were also soluble in the aforementioned solvents and stable up to around 350deg;C in both atmospheres. © 1994 John Wiley & Sons, Inc.
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  • 49
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 929-935 
    ISSN: 0887-624X
    Keywords: reduced titanium dioxide ; supported titanium tetrachloride ; ethylene polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Titanium tetrachloride heterogenized on reduced TiO2 has been studied as a catalyst for ethylene polymerization. The catalyst has good storage stability and exhibits good activity for ethylene polymerization. The polymer chains grow linearly during ca. 1 h, giving an average molecular weight of up to 2.5 × 106 which indicates that practically no β-elimination occurs. The activity of the catalyst at 50°C, based on Ti(III), is 7.6 × 106 PE/mol Ti h bar and based on the quantity of polyethylene formed it is 1.25 × 106 g PE/mol Ti h bar. The molecular weight of the polymer can be controlled with the addition of hydrogen, under 0.5 bar hydrogen, polyethylene with a molecular weight of 411,000 and a relatively low polydispersity index of 2.2 is obtained. The catalyst shows good thermal stability; the Arrhenius activation energy is 31.8 kJ/mol for the polymerization. The catalyst is also active for propylene polymerization, giving 3 × 106 g PP/mol Ti h bar with the high isotacticity of 93%. © 1994 John Wiley & Sons, Inc.
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  • 50
    ISSN: 0887-624X
    Keywords: ε-caprolactone ; ring-opening polymerization ; rare earth coordination catalyst ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ring-opening polymerization of ε-caprolactone has been carried out by using rare earth coordination catalysts for the first time. The rare earth compounds, RE(acac)3.3H2O, Nd(P204)3, Nd(P507)3, Nd(naph)3, Nd(BA)3.2H2O, etc. (where RE = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Lu, Y; acac = acetylacetone; BA = benzoylacetone), combined with trialkyl aluminum, greatly increased the degree of conversion and the molecular weight of poly(ε-caprolactone) (PCL). The influence of reaction conditions on the polymerization of ε-caprolactone catalyzed by the Nd (acac)3.3H2O-AlEt3 system has been examined in detail. The kinetics indicates that the polymerization rate has the first-order in monomer and a half-order in catalyst. The overall activation energy of the ring-opening polymerization amounts to 59.4 kJ/mol. By IR and UV-Vis spectra, 1H- and 13C-NMR data, it is assumed that the ring-opening polymerization of ε-caprolactone catalyzed by the Nd(acac)3.3H2O-AlEt3 system proceeds via complexation of monomer to catalyst, acyl-oxygen cleavage insertion propagation mechanism. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 683-697 
    ISSN: 0887-624X
    Keywords: hydrosilation ; epoxy monomers ; epoxy functional oligomers ; cationic photopolymerization ; regioselective hydrosilation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several series of multifunctional silicon-containing epoxide monomers and oligomers have been prepared using rhodium catalyzed hydrosilation reactions. Dialkyl and diarylsilanes can be condensed with vinyl epoxides to give high yields of the desired diepoxides while the hydrosilation of alkyl and aryl silanes yields a mixture of di and tri epoxy substituted products. The condensation of αω,—Si—H difunctional compounds with vinyl epoxides can be carried out regioselectively to give α-hydrogen-ω-epoxy intermediates, which can be further reacted with di and tri olefins bearing terminal double bonds to give a series of well characterized epoxy functional oligomers. An investigation of the photoinitiated cationic polymerization of the monomers and oligomers, which were prepared during the course of these studies, was carried out. © 1994 John Wiley & Sons, Inc.
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  • 52
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syndioselective propylene polymerization has been promoted by rac-2,2-dimethylpropylidene (1-η5-cyclopentadienyl) (1-η5-fluorenyl) dichlorozirconium (1). The active catalytic species were generated using either triphenylcarbenium tetrakis (pentafluorophenyl) borate (2) (Zr+ method) or methylaluminoxane (MAO method). The former exhibited much higher activity than the latter, especially at low polymerization temperatures (Tp). Syndiotactic poly (propylene) (s-PP) obtained at Tp = -20°C has Tm approaching 160°C, [rrrr] pentad fraction of 0.92 to 0.95, and 45% crystallinity (Xc). It crystallized in two antichiral unit cells B and C. The C structure is favored by low temperature of polymerization, slow crystallization from melt, and annealing. The s-PP has M̄w/M̄n ranging from 3.6 to 4.4, which can be separated into stereoregular fractions soluble in heptane and hexane and stereoirregular fractions soluble in pentane, ether, and acetone. Therefore, this system cannot be considered to be a single-site catalyst. A parallel study was made on the isopropylidene (1-η5-cyclopentadienyl) (1-η5-fluorenyl) dichlorozirconium (3)/MAO catalyst. Molecular mechanics calculations were performed for all combinations of the configuration of asymmetric centers. The steric energy favors syndiotactic enchainment for both catalysts 1 and 3, with 1 forming the more syndioselective catalyst. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 767-777 
    ISSN: 0887-624X
    Keywords: emulsion polymerization ; ion-free ; polybutadiene ; poly (vinyl pyrrolidone) ; polymer electrolyte ; latex ; core-shell ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of polybutadiene (PB) by emulsion polymerization with use of poly (vinyl pyrrolidone) (PVP) stabilizer was investigated. The goal was to prepare flexible latex films that clearly retain particle morphology in the solid state after heat treatment and contain no ionic, hydroxyl, or (primary, secondary) amino groups. The latex particle core composed of PB was nonpolar and rubbery, while the particle shell composed of PVP was polar and glassy. Average particle diameter was measured by the dynamic light scattering technique, and particles were imaged by scanning and transmission electron microscopic analyses. Dialysis of the latices resulted in successful exchange of the dispersion medium without precipitation. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 789-795 
    ISSN: 0887-624X
    Keywords: polycondensation ; serine ; aspartic acid ; inhibitors ; crystallization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Biocompatable, degradable polymers that are powerful inhibitors of mineral formation were synthesized by automated solid phase and thermal polycondensation techniques. These polymers are analogues of natural proteins isolated from CaCO3 biomineral and consist primarily of polyaspartic acid and serine or modified serine residues. Phosphorylation of the serine residues greatly enhanced the inhibitory activity of the polymers. Synthesis in the presence of orthophosphoric acid resulted in the decomposition and modification of serine. These modified residues when incorporated into the polyaspartic acid also enhanced inhibitory activity of the polymers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 841-847 
    ISSN: 0887-624X
    Keywords: ethylene-carbon monoxide copolymer ; propylene-carbon monoxide copolymer ; polythiophene ; polyfuran ; polyalcohol ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of the alternating ethylene-carbon monoxide copolymer with Lawesson's reagent resulted in the conversion of 75% of the carbonyl groups to thiophene units. A few thioketone groups were also present in the derived polymer. A polymer with furan units in the backbone was formed upon treatment of the alternating propylene-carbon monoxide copolymer with P2O5. Depending on the reaction conditions, up to 90% of the carbonyl groups were converted. Finally, 1,4-polyalcohols were prepared from the alternating propylene-carbon monoxide copolymer by reduction. Hydrogenation using Raney nickel as catalyst resulted in the reduction of 60% of the carbonyl groups, whereas reaction with LiAlH4 at room temperature caused the reduction of 85% of the carbonyl groups. The glass transition temperature was found to increase monotonically with increasing concentration of hydroxyl groups in the polymer backbone. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 879-887 
    ISSN: 0887-624X
    Keywords: living cationic polymerization ; isobutyl vinyl ether ; added Lewis base ; EtAlCl2 ; Et1.5AlCl1.5 ; polymerization mechanism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the living cationic polymerization of isobutyl vinyl ether (IBVE) by the CH3CH (OiBu) OCOCH3 (1)/EtAlCl2 initiating system in the presence of the added base in hexane at +40°C, the stability of the initiating system 1/EtAlCl2, which form initiating species CH3CH⊕ (OiBu) derived from 1, was investigated. In the presence of the Lewis base such as ethyl acetate or 1,4-dioxane, the active species was stable for 300 min even at +40°C in the absence of IBVE, and the living polymers were quantitatively obtained by adding IBVE. However, the active species was partly consumed by side reactions during the standing time for 60 min in the presence of a less basic additive such as ethyl benzoate, and about 50% of the active species was deactivated in the presence of methyl chloroacetate. Consequently, in the case of a less basic additive such as methyl chloroacetate (which was effective for the fast living polymerization), it can be seen that the careful selection of polymerization conditions was required. The living polymerization rate was dependent on the second order of EtAlCl2 concentration. EtAlCl2 induced the cleavage of 1 into CH3CH⊕ (OiBu) and EtAl⊖Cl2(OCOCH3), and the reactivity of CH3CH⊕ (OiBu) and propagating carbocation may be controlled by EtAl⊖Cl2(OCOCH3) with the aid of other EtAlCl2. Et1.5AlCl1.5 exists as a bimetallic complex of EtAlCl2 and Et2AlCl, and it is expected that the polymers having a bimodal molecular weight distribution will be obtained due to two kinds of counteranions coming from EtAlCl2 and Et2AlCl. However, in the cationic polymerization of IBVE by 1/Et1.5AlCl1.5 in the presence of ethyl acetate, the living polymer exhibiting a unimodal and very narrow molecular weight distribution was obtained. Thereby, it was suggested that the counteranions, EtAl⊖Cl2(OCOCH3) and Et2Al⊖Cl(OCOCH3), exchange rapidly with each other. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 917-928 
    ISSN: 0887-624X
    Keywords: radical polymerization ; stable phenoxyl radical ; intramolecular hydrogen transfer ; termination ; hindered phenol ; copolymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Radical polymerizations of methyl methacrylate (MMA), styrene (St), and vinyl acetate (VAc) were carried out in the presence of a novel phenyl acrylate derivative bearing a hindered phenol moiety (HPA). It has been clarified that HPA acts as a retarder and inhibitor for the polymerizations of MMA and VAc, respectively, and that in the polymerization of St it behaves as a monomer to give a copolymer. These additive effects were interpreted in terms of intramolecular transfer of the phenolic hydrogen in competition with propagation of the HPA radical to monomers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 961-969 
    ISSN: 0887-624X
    Keywords: ethylene ; copolymerization ; hindered piperidine ; UV stabilizer ; chemically bound antioxidant ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monomers having a norbornene as polymerizable group and a 2,2,6,6-tetramethyl piperidine as stabilizing moiety were prepared. This monomer was successfully copolymerized with ethylene using VAc3/AlEt2Cl as the catalytic system. Copolymers exhibited better stability under accelerated aging than polyethylene stabilized by classical blending with commercial hindered amines. Any attempt made to obtain copolymers using a high activity TiCl4/MgCl2 catalyst was unsuccessful. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 987-991 
    ISSN: 0887-624X
    Keywords: palladium-catalyzed polycondensation ; soluble ethynylene-containing polyamides ; ethynyl-containing amide monomers ; thermal behavior ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 993-995 
    ISSN: 0887-624X
    Keywords: metathesis ; regioselective polymerization ; 7-alkylnorbornenes ; ab initio MO Calculations ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 61
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 343-354 
    ISSN: 0887-624X
    Keywords: thermotropic polyester ; nematic ; X-ray diffraction ; synthesis ; characterization ; 3,4′-dihydroxybenzophenone ; 4,4′-bibenzoic acid ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of fully aromatic, thermotropic polyesters, derived from 3,4′-dihydroxybenzophenone and various aromatic dicarboxylic acids, was prepared by the high-temperature solution polycondensation method and examined for thermotropic behavior by a variety of experimental techniques. The aromatic dicarboxylic acids used in this study were 2,6-naphthalenedicarboxylic acid, 4,4′-bibenzoic acid, and terephthalic acid.The two homopolymers of 3,4′-DHB with either 2,6-NDA or 4,4′-BBA formed nematic LC phases at 285°C and 255°C and also exhibited isotropization transitions (Ti) at 317°C and 339°C, respectively. The copolymer of 3,4′-DHB with 50% TA and 50% 2,6-NDA also formed a nematic LC phase and had a broader range of LC phase than that of its respective homopolymers. Two other copolymers of 3,4′-DHB, both containing 50% 4,4′-BBA, also formed nematic LC phases at low Tf values. All of the thermotropic polyesters had high thermal stabilities. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 369-382 
    ISSN: 0887-624X
    Keywords: N-phenyl-3,3-bis[4-(p-aminophenoxy)phenyl] phthalimidine ; N-phenyl-3,3-bis (4-hydroxyphenyl) phthalimidine ; polyamides ; polyimides ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-Phenyl-3,3-Bis[4-(p-aminophenoxy)phenyl] phthalimidine (II) was used as a monomer with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to synthesize polyamides and polyimides, respectively. The diamine II was derived by a nucleophilic substitution of N-phenyl-3,3-bis(4-hydroxyphenyl) phthalimidine with p-chloronitrobenzene in the presence of K2CO3 and then hydro-reduced. Polyamides IVa-g having inherent viscosities of 0.55-1.64 dL/g were prepared by the direct polycondensation of the diamine II with various aromatic diacids using triphenyl phosphite and pyridine as condensing agents. All the aromatic polyamides were amorphous and readily soluble in various polar solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, dimethylsulfoxide, and N-methyl-2-pyrrolidone (NMP). Transparent and flexible films of these polymers could be cast from the DMAc solutions. These aromatic polyamides had glass transition temperatures in the range of 293-319°C and 10% weight loss occurred up to 480°C. The polyimides were synthesized from diamine II and various aromatic dianhydrides via the two-stage procedure that included ring-opening polyaddition in DMAc to give poly(amic acid)s, followed by thermal or chemical conversion to polyimides. Most of the aromatic polyimides obtained by chemical cyclization were found to be soluble in NMP, m-cresol, and o-chlorophenol. These polyimides showed almost no weight loss up to 500°C in air or nitrogen atmosphere. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1389-1392 
    ISSN: 0887-624X
    Keywords: methyl-(trifluoromethyl) acrylate ; propagation rate constant ; termination rate constant ; rotating sector method ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [no Abstrat]
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  • 64
    ISSN: 0887-624X
    Keywords: thermoplastic elastomers ; poly (-methylstyrene-b-isobutylene-b--methylstyrene) ; triblock copolymer ; living carbocationic polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparatory to triblock synthesis experiments, the cationic polymerization of α-methylstyrene (αMeSt) was investigated using the 2-chloro-2,4,4-trimethylpentane (TMPCI)/TiCl4 initiating system in the presence of triethylamine (Et3N) as electron donor (ED) and CH3Cl/n-hexane mixed solvent in the -80 to -40°C range. Conversions are influenced by temperature, [TiCl4], [Et3N], and [αMeSt]. The polymerization of αMeSt is living at -80°C: Both termination and chain transfer to monomer are frozen out, however, initiation is slow relative to propagation. Highly syndiotactic (〉94%) Pα Mest was obtained. At-60deg;C initiator efficiency is ca. 100%, but termination becomes evident. Et3N may act both as Ed and as proton scavenger. Novel poly(α-methystyrene-b-isobutylene-b-α-methylstyrene) (PαMeSt-PIB-PαMeSt) triblocks have been synthesized by adding αMeSt to biliving polyisobutylene carbocations (⊕PIB⊕) in the -80 to -40°C range. The effects of temperature, solvent polarity, and [Et3N] on the block copolymerization have been investigated. At -80°C, the rate of crossover from ⊕PIB⊕ to αMeSt is lower than that of propagation of PαMeSt⊕, so that the triblock is contaminated by PIB and PIB-b-PαMeSt. At -60°C, crossover occurs preferentially. The rate of propagation relative to that of crossover is also reduced by lowering the solvent polarity and increasing the [Et3N]. High crossover efficiency and blocking efficiency can be obtained under optimum blocking conditions. The triblocks are novel thermoplastic elastomers (TPEs). © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 451-456 
    ISSN: 0887-624X
    Keywords: hexamethylenediammonium adipate ; solid-state polycondensation (polyamidation) ; acid catalysts ; solid-melt transition ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Loss of diamine and distinct transition phenomena from the solid to the melt state restrain solid-state polymerization (SSP) of nylon salts from industrial application. To depress these phenomena temperatures well below the melting point of the starting material are employed, resulting however in low reaction rates. The need to use catalysts arises and accordingly in this study hexamethylenediammonium adipate (HMA) particles were polymerized containing a strictly controlled amount of uniformly distributed catalyst. The catalysts included boric, sulphuric, and phosphoric acids with boric acid being the most effective in accelerating the reaction while eliminating the tendency to agglomeration. In general, catalyst concentration up to a critical value plays a considerable role in the overall behavior. Furthermore, in agreement with non catalytic processes, the reaction temperature remains an influential parameter. © 1994 John Wiley & Sons, Inc.
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  • 66
    ISSN: 0887-624X
    Keywords: polyaddition ; phosphorus-containing polymer ; saturated polymer ; phenylphosphine ; 1,4-divinylbenzene ; 1,4-diisopropenylbenzene ; flame resistance ; thermal stability ; DSC ; TG ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A polyaddition of phenylphosphine (PH) to 1,4-divinylbenzene (DVB) or 1,4-diisopropenylbenzene (DIPB) was carried out by radical initiations or UV irradiation at 60-80°C in toluene under a nitrogen atmosphere. The soluble polymer with higher molecular weight ($\[ \bar M_w = 2 \times 10^4 \]$) was obtained in a high yield with AIBN initiator for 95 h in the presence of 5% excess of PH to DVB (monomer feed ratio [DVB]0/[PH]0 = 1/1.05). On the other hand, a polyaddition of PH to DIPB proceeded much slower than the case of DVB, but the high polymer was obtained in a high yield by choosing polyaddition conditions such as polyaddition temperature and initiator concentration. From 1H-NMR, IR analyses, and phosphorus content of the polymers, it was characterized that both polymers have the alternating structure consisting of PH and DVB or DIPB units in 1 : 1 ratio. The glass transition and decomposition temperatures of both polymers under a nitrogen atmosphere were almost similar: 15-30°C and 380-385°C, respectively; but, the polymers were oxidized by heating under an atmosphere of air. The polymers had a self-extinguishing property and the polymer blend of the flammable polymers such as polystyrene and polyethylene with the phosphorus-containing polymers exhibited an excellent flame resistance. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1295-1304 
    ISSN: 0887-624X
    Keywords: poly (ethylene naphthalate) ; transesterification kinetics ; reaction order ; activation energy ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The transesterification of dimethyl naphthalate (DMN) with ethylene glycol (EG) was kinetically investigated in the presence of various catalysts at 185°C. The transesterification was assumed to obey first-order kinetics with respect to DMN and EG, and a rate equation was derived. The rate constant of transesterification which was calculated from the quantity of methanol which distilled from the reaction vessel was used to evaluate the activity of each metal compound. The first-order dependence on the catalyst concentration is valid below a critical concentration which was found to be dependent on the catalyst type. The order of decreasing catalytic activity of various metal ions was found to be: Pb ≥ Zn 〉 Co 〉 Mg 〉 Ni ≥ Sb, but in the case of highly basic metal salts, the rate constants were found to be extremely large at the initial stage of the reaction, and then rapidly decreased with the progress of the reaction. Effects of reaction temperature were also discussed. The activation energies for zinc acetate and lead acetate were 97.84 and 108.8 kJ/mol, respectively, which were calculated from the Arrhenius equation. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1341-1350 
    ISSN: 0887-624X
    Keywords: addition polyimides ; biphenyldiamine ; benzidine ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new series of high flow PMR-type addition curing polyimides was developed, which employed the substitution of 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (BTDB) for p-phenylenediamine (p-PDA) in a PMR-II formulation. These thermoset polyimides, designated as 12F resins, were prepared from BTDB and the dimethyl ester of 4,4′-(hexafluoroisopropylidene)-diphthalic acid (HFDE) with either nadic ester (NE) or p-aminostyrene (PAS) as the endcaps for addition curing. The 12F prepolymers displayed lower melting temperatures in DSC analysis, and higher melt flow in rheological studies than the corresponding PMR-II polyimides. Long-term isothermal aging studies showed that BTDB-based 12F resins exhibited comparable thermo-oxidative stability to p-PDA based PMR-II polyimides. The noncoplanar 2- and 2′-disubstituted biphenyldiamine (BTDB) not only lowered the melt viscosities of 12F prepolymers, but also retained reasonable thermal stability of the cured resins. The 12F polyimide resin with p-aminostyrene endcaps showed the best promise for long-term, high-temperature application at 343°C (650°F). © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1377-1384 
    ISSN: 0887-624X
    Keywords: ozonization ; grafting ; kinetics ; radical polymerization ; EVAg-styrene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymers can be ozonized with an ozone/oxygen mixture to create peroxides and hydroperoxides on the polymer chain. These heat-sensitive functional groups can be used to initiate radical polymerization of vinyl monomers and give graft copolymers. The properties of these copolymers are well described in literature; however, we notice that available data concerning decomposition rate constants are inconsistent. Decomposition rate measurements, time of assay of free radicals and stability of the ozonized polymers do not give the same results. In this work, we studied the kinetics of the styrene polymerization initiated by an ozonized ethylene vinyl acetate copolymer. Consequently, the f·kd product can be calculated (f is the efficiency and kd the decomposition rate constant). The ozonized copolymer is not similar to usual radical initiators. The initial viscosity of the solution has an important effect on the calculation of the kinetic values. Activation energy and Arrhenius coefficient are different than the one obtained for the usual initiators. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 699-709 
    ISSN: 0887-624X
    Keywords: contact angle goniometry ; chemical derivatization ; plasma treatment ; polyethylene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma-oxidized polyethylene (O-PE) was derivatized with various chemicals and the advancing and receding contact angles with water, formamide, and tricresylphosphate were measured. The contact angles were used to evaluate the surface free energy (SFE) components in terms of the Lifshitz-van der Waals-acid base (LW-AB) model. The derivatization was directed to couple alkyl chains to carbonyl, hydroxyl, and carboxyl groups generated on the surface of O-PE. Carbonyl groups were treated with hydrazine and then reacted with dodecanoyl chloride. Hydroxyl groups were first reacted with reactive dicarboxylic acid dichlorides or cyanuric chloride, respectively, and then with alkylamines because the direct bonding of long-chain alkyl carboxylic acid chlorides proceeds slowly and is, therefore, completed by surface restructuring. Carboxyl groups were chlorinated and in a second step reacted with alkylamines. The bonding of C12-alkyl chains can be sensitively detected by the LW part of the SFE. Concerning the receding contact angles, it is pointed out that the carbonyl groups are present on the surface in a higher concentration than hydroxyl and carboxyl groups. The combination of contact angle goniometry (CAG) and chemical derivatization reactions supplies semiquantitative information about functional groups in the uppermost surface layer. In this way, a major shortcoming of CAG can be overcome. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 741-746 
    ISSN: 0887-624X
    Keywords: polymerization mechanism ; polymerization kinetics ; carbonate macrocyclization ; polycarbonate ; stopped-flow spectroscopy ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of phenylchloroformate (PCF) reactions have been used to model some of the key chemical events in carbonate macrocyclization. Three reactions have been studied using stopped-flow FT-IR spectroscopy: formation of acyl ammonium salt from PCF and three different trialkylamines, the conversion of acyl ammonium salt to urethane, and the condensation reaction between acyl ammonium salt and 4-isopropylphenol. The rate dependence was studied for triethylamine (TEA), diethylmethylamine (DEMA) and tri-n-butylamine (TBA) at 0°C in anhydrous CH2Cl2. The reactivity order for acyl ammonium salt formation for TBA: TEA: DEMA is 1 : 2.7 : 〉444. By contrast, condensation and urethane formation are not sensitive to the structure of the amine. The rate of condensation is comparable to the rate of acyl ammonium salt formation for TEA and TBA, while the rate of urethane formation is the slowest process for all three amines. These results are consistent with the view that the yield of macrocyclic polycarbonates is related to the concentration of the acyl ammonium salt. The optimum amine concentration for obtaining high yields of cyclics varies with the amine structure and parallels the difference in the rates of acyl ammonium salt formation. © 1994 John & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1471-1480 
    ISSN: 0887-624X
    Keywords: methyl methacrylate ; redox polymerization ; kinetics ; mechanism ; additives ; iron saccharinate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The role of N,N-dimethyl-p-toluidine (DMPT) and saccharin as accelerators in the polymerization of methyl methacrylate initiated by the redox decomposition of cumene hydroperoxide (CHP) in the presence of iron saccharinate has been kinetically investigated. DMPT reduces ferric ions to ferrous ions, so that an equilibrium is established between the two oxidation states. With the assumption of a steady-state concentration of propagating radicals, the rate of initiation was deduced from the rate of polymerization and the kinetic orders with respect to each compound involved in the initiation step have been determined. The reaction is first-order in CHP, iron saccharinate, and saccharine and second-order in DMPT. In a proposed scheme, Fe2+ ions, complexed by two DMPT molecules, are much more reactive than uncomplexed Fe2+ and saccharin activates the decomposition of CHP by protonation of the O—O bond. This mechanism, similar to that proposed in the case of copper saccharinate, explains the synergistic effect of both accelerators. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1523-1530 
    ISSN: 0887-624X
    Keywords: amphiphilic polymers ; graft copolymers ; poly(oxyethylene) ; activated esters ; emulsifying properties ; thermal properties ; crystallinity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Amphiphilic graft copolymers were synthesized via activated ester substitution of derivatives of fumaric acid with amino-functionalized methoxypoly (oxyethylene)s (MPEO-NH2) of different molecular weights. The monomeric activated esters, isopropyl pentachlorophenyl fumarate (PCPFA) and isopropyl succinimido fumarate (SIFA), were copolymerized with styrene (St) or N-vinyl pyrrolidone (VP) at equimolar ratio. The polymeric-activated esters proved to be good precursors for grafting of definite amounts of MPEO-NH2. The aminolysis of the succinimide esters and VP-containing copolymers proceeded with gel formation due to extensive hydrogen bonding. The hydrodynamic behavior, the emulsifying ability, the thermal properties, and crystallinity of the graft copolymers were studied as a function of their molecular characteristics. The length of the PEO grafts and the degree of grafting are the factors which affect the melting parameters and the crystallinity of the side chains. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1551-1555 
    ISSN: 0887-624X
    Keywords: poly(vinyl pyrrolidone) ; cationic polymerization ; electropolymerization ; thin films ; surface modification ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electroinitiated polymerization of N-vinyl-2-pyrrolidone has been investigated. After electrolysis at controlled potential, a thin, covering, and homogeneous film of poly(N-vinyl-2-pyrrolidone) appears on the electrode. The insolubility of the polymer in its classical solvents implies the existence of a true chemical grafting of macromolecules on the platinum surface. Chain propagation occurs by a cationic mechanism initiated by a direct electron transfer leading to grafted cations on the surface, followed by the nucleophilic attack of neutral molecules. The molecular weight of the polymer was estimated by gel permeation chromatography after having mechanically removed the film from the electrode. A molecular weight distribution curve showing an average value of 16,000 was observed. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1569-1579 
    ISSN: 0887-624X
    Keywords: functional group gradients ; corona discharge ; graft copolymerization ; water contact angles ; FTIR-ATR ; ESCA ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Functional group gradient surfaces where the density of functional groups changes gradually along the sample length were prepared. The functional group (— COOH, — CONH2, and — OH group) gradient surfaces were produced by the treatment of low-density PE sheets using a corona with gradually increasing power, followed by the graft copolymerization of acrylic acid and subsequent substitution reaction of carboxylic acid groups to amide or hydroxyl groups. The prepared gradient surfaces were characterized by the measurement of water contact angle, FTIR-ATR, and ESCA. The gradient surfaces prepared can be used to systematically investigate the interactions of biological or other species in terms of the surface functional groups and their density of polymeric materials. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1609-1617 
    ISSN: 0887-624X
    Keywords: selenium-containing polymer ; radical addition polymerization ; 1,4-benzene-diselenol ; 1,4-divinylbenzene ; 2,2′-azobisisobutyronitrile ; dimethyl 2,2′-azobisisobutyrate ; 1,1′-azobis(1-acetoxy-1-phenylethane) ; model addition reaction ; side reaction ; properties of polymer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A novel addition polymerization of 1,4-benzenediselenol (BDSe) to 1,4-divinylbenzene (DVB) was carried out with various azo radical initiators [dimethyl 2,2′-azobisisobutyrate (DAIB), 1,1′-azobis(1-acetoxy-1-phenylethane) (AAPE), and AIBN] in toluene at 65 and 75°C under a nitrogen atmosphere. The polymerization proceded without an induction period, and pale-yellowish powder polymers were obtained in 89% yields for 75 h (DAIB), 89% yields for 24 h (AAPE), and 60% yields for 8 h (AIBN). The molecular weight (Mw) of the insoluble polymers in toluene was about 4000 (IBN) to 14,000 (DAIB or AAPE) by GPC. The polymer had an alternating structure of BDSe to DVB units by 1H-NMR, IR analyses, and selenium contents, but the polymer contained the diselenide linkage by Raman spectroscopy. By AIBN initiator, the yield of the polymers did not increase over 60% and higher molecular weight polymer was hardly obtained. According to the model addition reaction of benzeneselenol to styrene by AIBN, it was found that AIBN was consumed by the side reaction between dimethyl-N-(2-cyano-2-propyl)ketenimine derivedAppl 11 from AIBN and benzeneselenol to give the adduct C, MH+ 295 by DCI MS. On the other hand, DAIB and AAPE initiators, which do not form a ketenimine intermediate, gave the polymers of higher molecular weight in a higher yield. The polymer film exhibited high refractive index (n25D = 1.81) and a reversible phase transition between a transparency and an opaque by thermal mode. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1657-1664 
    ISSN: 0887-624X
    Keywords: photofunctionalization ; photocrosslinking ; synthetic membranes ; permselectivity ; pervaporation ; surface properties ; tetrazole ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new type of membrane polymer, containing a photosensitive moiety, was synthesized. The photochemically induced functionalization and crosslinking of poly [acrylonitrile-co-butadiene-co-styrene-co-2-(4-ethenyl) phenyl-5-phenyl-2H-tetrazole], ABSV, has been studied. A variety of dipolarophiles and phenolic compounds were applied to alter the polarity of the membrane surface. The functionalization and crosslinking were initiated by photoirradiation. DSC and contact angle measurements were used to characterize the modified polymer. Pervaporation experiments with a cyclohexane/benzene mixture (5 wt% benzene) were carried out, with the results showing, that the photochemical treatment significantly effects both permselectivity and flux. Solubility parameters were found to be useful to interpret the pervaporation data. In general, the selectivity towards benzene increases with the polarity of the membrane surface, i.e., with increasing polarity of the modifier. A mechanism to explain the influence of both functionalization and crosslinking on the membrane performance, is proposed. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1691-1702 
    ISSN: 0887-624X
    Keywords: grafting ; basic functionalization ; free radical polymerization ; methacrylate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The grafting of 2-(dimethylamino)ethyl methacrylate (DMAEMA) onto two model hydrocarbons, squalane and n-eicosane, and to linear low density polyethylene (LLDPE) has been investigated. The results of the study indicate that a high reaction temperature, 160°C, and a low concentration of monomer, less than 0.3 M, are optimum conditions for the grafting reaction. Reaction products, which consisted of grafted hydrocarbons and poly(DMAEMA), were separated by solvent extraction and vacuum distillation; samples were then analyzed by NMR and FTIR spectroscopy and size exclusion chromatography. 1H-NMR spectroscopy indicates that grafted squalane contained approximately 6 DMAEMA units per squalane residue. 1H- and 13C-NMR and molecular weight studies strongly suggest that the grafts onto the model hydrocarbons consist of single DMAEMA units. Results of the melt grafting of DMAEMA onto LLDPE show that the grafting efficiency and degree of grafting are substantially lower than were expected from the model system. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1977-1982 
    ISSN: 0887-624X
    Keywords: poly(arylamino-quinone)s ; p-benzoquinone ; aromatic diamine ; tetrahydrofuran ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several poly(arylamino-quinone)s (PAAQs) were prepared by the conventional solution polymerization of p-benzoquinone with various aromatic diamines in tetrahydrofuran. Polymers prepared by this method were found to be more soluble in many organic solvents compared to the PAAQs prepared by other reported methods. The poly(arylamino-quinone)s were obtained in 82.3-94.5% yield and had inherent viscosities in the range of 0.073-0.251 dL/g. Among the PAAQs, the polymer prepared from p-benzoquinone and 1,3-bis(3-aminophenoxy)benzene (APB) had demonstrated exceptionally good solubility and thermal stability. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2003-2010 
    ISSN: 0887-624X
    Keywords: kinetics of polyesterification ; effect of diol chain length ; unsaturated polyesters ; energy of activation ; rate of reaction ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetics of polyesterification of maleic anhydride with polyethylene glycol (PEG) of varying molecular weights have been evaluated. The investigations have been carried out by employing heating cycles comparable to those employed in industrial processes and under nonisothermal conditions. The rate of reaction was found to decrease with increase in the chain length of the polyether. The energy of activation was estimated as 26.91, 40.25, and 47.30 Kcal/mol for PEG of molecular weights 200, 300, and 400, respectively. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2029-2038 
    ISSN: 0887-624X
    Keywords: 1,2-bis(p-vinylphenyl)ethane ; divinylbenzene ; crosslinker ; network structure ; size exclusion chromatography resins ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New size exclusion chromatography (SEC) resins based on a crosslinker having independent vinyl groups have been produced and compared with SEC resins based on divinylbenzene-55 (DVB). 1,2-Bis(p-vinylphenyl)ethane (p,p-BVPE) and its meta-isomers were suspension-copolymerized with p-methylstyrene in the presence of different porogens to give particles of about 5 μm average diameter. The porous particles were slurry-packed into stainless steel columns for SEC evaluation. Calibration curves were obtained using narrow disperse polystyrene standards with molecular weights ranging from 580 to 3,040,000. The calibration curves for the new BVPE resins covered wider useful molecular weight ranges than those for comparable divinylbenzene resins. Particle size, surface morphology and the properties of pores were studied using a Coulter Multisizer II, scanning electron microscopy, nitrogen adsorption, and mercury porosimetry. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2065-2071 
    ISSN: 0887-624X
    Keywords: poly(ether-ketone-amide) ; palladium-catalyzed polycondensation ; aromatic dibromide ; carbon monoxide ; thermal behavior ; tensile properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aromatic poly(ether-ketone-amide)s were prepared by the palladium-catalyzed polycondensation of aromatic dibromides containing ether ketone units, aromatic diamines, and carbon monoxide. Polymerizations were carried out in N,N-dimethylacetamide (DMAc) in the presence of palladium catalyst, triphenylphosphine, and 1,8-diazabicyclo [5,4,0]-7-undecene (DBU), and resulted in poly(ether-ketone-amide)s with inherent viscosities up to 0.82 dL/g under mild conditions. The polymers were quite soluble in strong acid, dipolar aprotic solvents, and pyridine. Thermogravimetry of the polymers showed excellent thermal stability, indicating that 10% weight losses of the polymers were observed in the range above 400°C in nitrogen atmosphere. The glass transition temperatures of the polymers were about 200°C, which are higher than those of poly(ether-ketone) analogues. These polymers also showed good tensile strength and tensile modulus. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1393-1397 
    ISSN: 0887-624X
    Keywords: cyclic carbonate ; epoxide ; cationic copolymerization ; spiro orthocarbonate ; ring-opening polymerization ; poly (ether-carbonate) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [no Abstrat]
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1423-1430 
    ISSN: 0887-624X
    Keywords: block copolymers ; free radical polymerization ; polydimethylsiloxane ; chain transfer ; rate constants for the transfer reactions ; thiuram disulfide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chain transfer constants (Ctr) for thiuram disulfide (TD) groups, included in the backbone of polydimethylsiloxane (PDMS) of different chain lengths, in methyl methacrylate (MMA) and styrene (St) were determined from measurements of the degree of polymerization. Two methods were used. The first consisted of using the initiation and transfer properties of the thiuram disulfides groups, and the second, of using a more efficient free radical initiator than TD groups, in which case the former behaves only as a transfer agent. In both the methods, the Ctr of TD was evaluated in bulk polymerization of MMA at 60, 70, 80, and 90°C. Using the first method, the Ctr of TD was measured also in solution polymerization of MMA in toluene at 100°C and, with the second one, in bulk polymerization of styrene at 60, 80, and 90°C. PDMS-based macrothiuram disulfide (macroiniferter) behaves as an “azeotropic” transfer agent for MMA and styrene at 125°C and 110°C, respectively. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2147-2153 
    ISSN: 0887-624X
    Keywords: polyaniline ; derivatives ; doping ; processing ; films ; gel ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High molecular weight poly(o-methoxyaniline) was synthesized using a novel method in which the polymerization occurs in the presence of a neutral salt. The molecular weight of the polymer was greatly affected by the quenching procedure employed to conclude the polymerization. Conventional doping of the base form of poly(o-methoxyaniline) produced a yellow coloration of the doping solution and polymer degradation. It was found that the molecular weight of the polymer decreased significantly after washing or doping with certain aqueous acid media. The gelation conditions of N-methyl pyrrolidinone (NMP) solutions and film preparation were also investigated for polymers of various molecular weights. The gelation time in NMP decreased drastically with the increase in the polymer molecular weight (the same for solution concentration and temperature), until a critical point was reached after which its decrease was very slow. Flexible, free-standing, and stretchable films were readily obtained from the higher molecular weight polymers. Good quality doped gel films with conductivity of up to 1 S/cm were obtained under optimized doping conditions. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2177-2185 
    ISSN: 0887-624X
    Keywords: photo-initiated base-formation ; polymer matrix ; O-acyloxime ; photolysis ; yield of amine ; acyloxyimino group ; thermal crosslinking ; recombination ; cage effect ; 6-membered cyclic intermediate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It was found that amines were formed efficiently by the photolysis of O-acyloximes followed by hydrolysis in polystyrene films and the relationship between structures of O-acyloximes and yields of amines were investigated. O-phenylacetyl acetophenone oxime (PaApO), O-pivaloyl acetophenone oxime (PApO), and O-benzoyl acetophenone oxime (BApO) as monofunctional O-acyloximes and O,O′-succinyl diacetophenone oxime (SDApO) and O,O′-glutaryl diacetophenone oxime (GDApO) as bifunctional O-acyloximes were examined. The yields of amines for PaApO and SDApO under N2 were ca. 70%, which was the highest among O-acyloximes examined in this experiment. On the other hand, the yields for PApO, BApO, and GDApO were less than 15% and it was verified that the hydrogen abstraction by imino radicals via 6-membered cyclic intermediates resulted in the lowering of yields. Although the effect of oxygen under photolysis on the yields of amine for PaApO was negligible under 50% conversion of PaApO, the yield decreased with further increase in the conversion and was 50% at 90% conversion. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2229-2234 
    ISSN: 0887-624X
    Keywords: tetrafluoroethylene ; propylene ; emulsion redox copolymerization ; fluoroelastomers ; reaction conditions ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Emulsion polymerization of tetrafluoroethylene and propylene with ammonium perfluorooctanoate, initiated by a redox system containing tert-butylperbenzoate (TBPB) was carried out. The effect of the components of the redox system Is (TBPB, FeSO4.7H2O, ethylenediamine tetraacetic acid (EDTA), and CH2(OH)SO2Na.2H2O) on the polymerization rate (R) and molecular weight ($\[ \bar M_n \] $) was studied. Among redox system components, Fe2+ concentration exerts the most significant effect (by power of 0.54) on the polymerization rate. It was found that R ∝ [Is]0.2-0.54 and Mn ∝ [Is]0.0-0.1 and polymerization reaction scheme was suggested for the action of the initiating system. The influence of the copolymerization conditions (pressure, temperature, stirring speed, and pH) is also discussed. The apparent activation energy of the reaction was found to be 46.0 kJ/mol. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2203-2221 
    ISSN: 0887-624X
    Keywords: cyanate ; epoxy ; mixed resins ; curing ; cross reaction ; 13C-, 15N-, and 1H-NMR ; oxazolidinone ; carbamate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The possible cross reactions indicated by solid-state NMR between cyanate functionalized resin and epoxy functionalized resin have been investigated by using both natural abundance and labeled monofunctional model compounds. These soluble products were isolated and purified by silica gel adsorption chromatography and gel permeation chromatography. They were fully characterized by high resolution 1H-, 13C-, 15N-NMR spectroscopy and by mass spectrometry. The major cross-reaction product is a racemic mixture of enantiomers, which contain an oxazolidinone ring formed by one cyanate molecule and two epoxy molecules. However, epoxy consumption lags cyanate consumption in the overall reaction as triazine formation from the cyanate is much faster than the two competing reactions, the cross reaction between cyanate and epoxy, and the self-polymerization of epoxy, under the conditions investigated. The cross reaction between cyanate and epoxy is limited. Approximately 12% of cross reaction between cyanate and epoxy was found in the overall reaction. In addition to the cross reactions of epoxy and cyanate, the reactions of epoxy and the carbamate, which is the major side product for the curing reaction of cyanate resin in solution, have also been investigated, and the mechanism of these reactions discussed. From the reactions of epoxy and carbamate, several products related to cross reaction between epoxy and cyanate have been isolated and identified. It is suggested that the reaction of epoxy and carbamate is one of the pathways in the overall cross reaction between epoxy and cranate resins. Finally, the mechanism of the overall cross-curing reaction between the diepoxy and dicyanate mixed resins is discussed. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2241-2249 
    ISSN: 0887-624X
    Keywords: iniferter ; living radical polymerization ; photopolymerization ; spin trapping ; dithiocarbamate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The photodissociation of several N,N-diethyldithiocarbamate derivatives (RDC), i.e., benzyl, 1-phenylethyl, 2-phenylethyl, n-butyl, sec-, and tert-butyl N,N-diethyldithiocarbamates, was investigated by the spin trapping technique to elucidate the polymerization mechanism of styrene (St) with RDC as iniferters. The scission of RDC occured at two different C—S bonds depending on the structure of the alkyl groups of RDC and the cleavage manner was dominated by both resonance and steric effects. It has been confirmed that RDC generating an N,N-diethyldithiocarbamyl radical acts as an effective iniferter and induces the living radical polymerization of St in homogeneous system. The polymerizations of St with tetraethylthiuram disulfide and p-xylylene bis(N,N-diethyldithiocarbamate) were also discussed on the basis of the results of the spin trapping for RDC as the model compounds of the poly(St) chain ends. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1481-1496 
    ISSN: 0887-624X
    Keywords: aliphatic-aromatic poly(amide-imide) ; trimellitic anhydride ; ω-amino acids ; triphenyl phosphite ; direct polycondensation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Seven imidodicarboxylic acids II-1 to 5, II-10, and II-11 were prepared from trimellitic anhydride and ω-amino acids, such as glycine, β-alanine, 4-aminobutyric acid, 5-aminopentanoic acid, 6-aminohexanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Several aliphatic-aromatic poly(amide-imide)s were prepared by triphenyl phosphite promoted polycondensation reaction from the combination of 3-(4-carboxyphthalimido)propionic acid (II-2) or 6-(4-carboxyphtalimido)hexanoic acid (II-5) with various aromatic diamines and of all the imidodiacids with p-phenylenediamine or 4,4′-oxydianiline. All poly(amide-imide)s were characterized by inherent viscosity, gel permeation chromatography (GPC) measurements, solubility, tensile test, wide-angle X-ray scatting patterns, differential scanning calorimetry (DSC) measurements, and thermogravimetric (TGA) analyses. Effects of structural changes such as polymethylene length and diamine moieties on the properties of poly(amide-imide)s were studied. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1539-1542 
    ISSN: 0887-624X
    Keywords: polymerization ; ethylene ; polyethylene ; catalyst ; zeolites ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ethylene polymerization has been studied in the presence of catalyst based on vanadium or vanadium-chromium supported on a zeolite HY. The effect of vanadium over chromium has been investigated as a function of the sequence of exchange of metals on the support and metal contents. Both effects were investigated in relation to the characteristics of the polyethylene (PE) obtained. Low activity has been found for the V (II) zeolite HY catalyst. Moreover, vanadium acts either as an inhibitor or as a promoter for the polymerizing activity of the Cr (III)/zeolite catalyst, depending on the preparation method. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2223-2227 
    ISSN: 0887-624X
    Keywords: bulk ; copolymerization ; reactivity ratios ; methyl acrylate ; vinyl esters ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The course of composition drift in copolymerization reactions is determined by reactivity ratios of the contributing monomers. Since polymer properties are directly correlated with the resulting chemical composition distribution, reactivity ratios are of paramount importance. Furthermore, obtaining correct reactivity ratios is a prerequisite for good model predictions. For vinyl acetate (VAc), vinyl 2,2-dimethyl-propanoate also known as vinyl pivalate (VPV), and vinyl 2-ethylhexanoate (V2EH), the reactivity ratios with methyl acrylate (MA) have been determined by means of low conversion bulk polymerization. The mol fraction of MA in the resulting copolymer was determined by 1H-NMR. Nonlinear optimization on the thus-obtained monomer feed-copolymer composition data resulted in the following sets of reactivity ratios: rMA = 6.9 ± 1.4 and rVAc = 0.013 ± 0.02; rMA = 5.5 ± 1.2 and rVPV = 0.017 ± 0.035; rMA = 6.9 ± 2.7 and rV2EH = 0.093 ± 0.23. As a result of the similar and overlapping reactivity data of the three methyl acrylate-vinyl ester monomer systems, for practical puposes these data can be described with one set of reactivity data. Nonlinear optimization of all monomer feed-copolymer composition data together resulted in rMA = 6.1 ± 0.6 and rVEst = 0.0087 ± 0.023. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2235-2239 
    ISSN: 0887-624X
    Keywords: tetrafluoroethylene ; propylene ; emulsion redox copolymerization ; fluoroelastomers ; polymerization mechanism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Emulsion copolymerization of tetrafluoroethylene (TFE) and propylene (P) initiated by trilon-rongalite catalytic system containing tert-C4H9OH, initial monomer mixture, emulsifier (C7F15COONH4) concentration, and monomer mixture/water ratio on the polymerization rate (R) and molecular weight (M̄n) was investigated. Both R and M̄n increased considerably with TFE content in monomer mixture up to 75 mol %. Alternating rubber-like copolymers in a wide range of initial monomer mixture (from 55-85 mol %) were obtained. The reactivity ratio was found to be rTFE = 0.005 ± 0.04 and rp = 0.17 ± 0.07. Above the critical miscelle concentration, the effects of the initiating system Is and emulsifier Cs on R and M̄n were found to obey the following relations: \documentclass{article}\pagestyle{empty}\begin{document}$$ {R \propto [Is]^{0.54} \times [Cs]^{0.42} }\quad {{\rm and}}\quad {\bar M}_n \propto [Is]^{ - 0.1} \times [Cs]^{0.1} ,$$\end{document} according to which emulsion copolymerization proceeds by the I case of Smith-Ewart theory. Polymerization mechanism of the reaction studied was suggested. The copolymerization is mainly terminated by degradative chain transfer of the propagating radicals to propylene. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2251-2255 
    ISSN: 0887-624X
    Keywords: grafting ; spectroscopy ; N-vinyl carbazole ; cellulose-acetate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-vinyl carbazole (VCZ) was grafted on cellulose acetate film using simultaneous cobalt-60-γ ray irradiation grafting technique. Absorption, excitation, and emission spectral studies on the grafted film were carried out to ascertain the grafting of VCZ on the polymer matrix. Laser-flash photolysis studies with the solution of grafted film indicate the opening of the double bond of VCZ, which leads to the grafting. On the basis of the observed results, the mechanism of grafting in the system was proposed. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1877-1883 
    ISSN: 0887-624X
    Keywords: insoluble chelating polymers ; thiol ligand ; poly(ethylene glycols) chains ; functional polymers ; heavy metal ion recovery ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of chelating resins, derived from a macroreticular styrene-divinylbenzene (2%) copolymer beads grafted with various poly(ethylene glycols) HO—(—CH2—CH2—O—)n—H(n = 0, 4, 9, 13) and containing thiol groups as chelating functions, have been synthesized in a three-step reaction sequence. The structure of the functionalized resins was confirmed by IR spectrophotometry, elemental analysis, and differential scanning calorimetry. The complexation behavior of these thiol resins was investigated towards Hg(II), Cu(II), and Pb(II) ions in aqueous solution by a batch equilibration technique. The influence of pH on adsorption capacity was also examined. The adsorption values for metal ions' intake followed the order Hg(II) 〉 Cu(II) 〉 Pb(II). The affinity of these polymers towards Hg(II) ions was so high that the total mercury level in the liquid decreased from 20 ppm to below 10 ppb after 2 h of treatment. Polymers can be regenerated by washing with a solution of hydrochloric acid (6N) and 10% by weight of an aqueous solution of thiourea. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2543-2549 
    ISSN: 0887-624X
    Keywords: oxetane ; 19F-NKR ; triflic ; ring opening ; cationic polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The nature of ring-opening polymerization of oxetane derivatives initiated by triflic acid and triflic anhydride was investigated via 19F-NMR spectroscopy. Two types of propagating species, which were directly observed from the 19F-NMR spectra, were found to be oxonium macroions and triflic macroesters. These two propagating species established and equilibrium relationship during the polymerization process. The forming of oxonium macroion active species was highly dependent upon the substituents of the oxetane ring, and were enhanced when a more polar solvent was employed. The initiator effect, which occurred primarily in the initiating stage of the polymerization, is also discussed. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2565-2576 
    ISSN: 0887-624X
    Keywords: acrylate monomers ; polymerization kinetics ; stereostructure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of new unsaturated monomers containing functional groups has been theoretically analyzed by considering a simple kinetic scheme. In the reactions between acetyl and acryloyl chloride with neopentylglycol, it was shown that the comparison between theoretical and experimental results, does not allow us to conclude that the two rate constants controlling the reactions are equivalent. Kinetic experiments of the polymerization of 3-hydroxyneopentyl acrylate were carried out in benzene and 1,4-dioxane solution at different temperatures. Dilatometric techniques and nonlinear least-squares methods were used to obtain kinetic data and to determine the kinetic constants, respectively. The values of \documentclass{article}\pagestyle{empty}\begin{document}$k_p /k_t^{1/2}$\end{document} for this monomer were found higher in dioxane than in benzene due, probably, to the fact that in the last solvent the polymerization is heterogeneous. The activation energy, determined by using different values of \documentclass{article}\pagestyle{empty}\begin{document}$k_p /k_t^{1/2}$\end{document} was found 7.6 kcal/mol. The stereostructure of the polymers derived from 3-hydroxyneopentyl acrylate and 3-acetoxyneopentyl acrylate was determined by 13C-NMR spectroscopy from the analysis of the resonance signals belonging to the carbonyl groups, obtaining values for the fraction of isotactic dyads in the range 0.36 ± 0.03 for both polymers. Finally, the glass transition temperatures of both polymers, determined calorimetrically, were found 281 and 255 K, respectively. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1899-1902 
    ISSN: 0887-624X
    Keywords: poly(p-phenylenebenzobisoxazole) ; poly(terephthalic acid anhydride) ; 1,3-diamino-4,6-dihydroxybenzene ; polyphosphoric acid ; intrinsic viscosity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High molecular weight poly(p-phenylenebenzobisoxazole) (PBO) was prepared from poly(terephthalic acid anhydride) (PTAA) and 1,3-diamino-4,6-dihydroxybenzene dihydrogenchloride in polyphosphoric acid (PPA). PTAA may react directly with the o-aminophenol groups to form benzoxazoles or react with PPA to generate terephthalic acid (TA) of very small particle size, which dissolves readily in PPA. PTAA provides the advantages of bypassing the requirement of small particle size TA, reducing the amount of water liberated by half, and possibly providing faster kinetics in PBO synthesis. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1923-1929 
    ISSN: 0887-624X
    Keywords: thermotropic copolyamides ; p-aminobenzoic acid ; p-phenylenediamine ; monomer sequence ; triethyleneglycol bis(4-carboxyphenyl)ether ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolycondensations of triethyleneglycol bis(4-carboxyphenyl)ether (PEG3), p-amino-benzoic acid (PABA), and p-phenylenediamine (PPD) were studied in order to examine the effect of monomer sequences in the copolyamides upon the transition temperatures of the resulting copolymers. Random copolymerization of these monomers resulted in the copolymers exhibiting a nematic mesophase in a wide range of PABA content. On the other hand, the sequential copolymers composed of PABA/PPD = 1/1 and 2/1, which were prepared from 4,4′-diaminobenzanilide (DABA) and N,N′-bis(4-aminobenzoyl)-p-phenylenediamine (BAB-PPD), respectively, did not show a mesophase. The copolymers of a diamine combination of DABA and PPD exhibited a nematic mesophase, despite the lack of a mesophase for each homopolymer. The combinations of DABA and other diamines were also examined. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1957-1968 
    ISSN: 0887-624X
    Keywords: radical polymerization ; alkyl crotonate ; 1,2-disubstituted ethylene ; propagation rate constant ; termination rate constant ; substituted polymethylene ; thermal property ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Radical polymerization of several alkyl crotonates (RCr) was carried out in bulk or in benzene in the presence of radical initiators. Homopolymerization of RCr bearing bulky ester alkyl groups, e.g. tert-butyl (tBCr), 1-adamantyl (AdCr), and 3,5-dimethyl-1-adamantyl crotonate (DMAdCr) proceeded to give a polymer with molecular weight of several thousands despite of the steric hindrance and chain transfer by the presence of the β-methyl group, while the methyl and ethyl esters gave no polymer. The kinetics of the polymerization was examined in detail and absolute rate constants were evaluated by means of electron spin resonance spectroscopy. The propagation rate constants of RCr were 0.41-1.0 L/mol s, being much smaller than those of the corresponding methacrylates (530-570 L/mol s). The termination rate constants were also determined from the analyses of steady state and non-steady state polymerizations. Radical copolymerizations of AdCr (M2) with several vinyl monomers (M1) were carried out in bulk at 60°C and the rate constants for cross propagations were calculated to examine reactivities of the monomer and its polymer radical. The structure and thermal properties of the resulting poly (AdCr) were also investigated. Onset temperature of decomposition and glass transition temperature of poly(AdCr) were revealed to be much high as 302 and 234°C, respectively. © 1994 John Wiley & Sons, Inc.
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