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  • 1
    Electronic Resource
    Electronic Resource
    Highly chemoselective addition of (o-nitrobenzyl)silanes to nonenolizable aldehydes (1987)
    s.l. : American Chemical Society
    The @journal of organic chemistry 52 (1987), S. 4381-4384 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo00228a043
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  • 2
    Electronic Resource
    Electronic Resource
    Elastomeric properties of ethylene/propylene copolymers prepared by zirconocene/methylaluminoxane catalysts (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 229 (1995), S. 113-122 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ethylen/Propylen-Copolymere (EPM) wurden durch Suspensionspolymerisation in flüssigem Propylen hergestellt, wobei homogene Katalysatoren vom Typ der nicht überbrückten Zirkonocene und Methylaluminoxan (MAO) verwendet wurden. Mit Bis(η5-cyclopentadienyl)zirkondichlorid (Cp2ZrCl2), Bis(η5-cyclopentadienyl)dimethylzirkon (Cp2ZrMe2) und Bis(η5-cyclopentadienyl)dibenzylzirkon (Cp2ZrBz2) als Katalysatoren wurden EPM mit niedrigem mittlerem Molekulargewicht (MW) und, im allgemeinen, in geringer Ausbeute erhalten. Hingegen wurde ein ganz erheblicher Anstieg der Produktivität und des MW verzeichnet, wenn Bis(η5-indenyl)zirkondi-chlorid (Ind2ZrCl2) und Bis(η5-indenyl)dimethylzirkon (Ind2ZrMe2) sowie auch Bis(η5-tetrahydroindenyl)zirkondichlorid [(Ind H4)2ZrCl2] in Kombination mit MAO eingesetzt wurde. Insbesondere ermöglichte es letzteres Katalysatorsystem, EPM mit engerer Molekulargewichtsverteilung verbunden mit den oben genannten Eigenschaften zu erhalten. Bessere rheologische und elastische Eigenschaften konnten auch festgestellt werden bei rohen und vulkanisierten Proben, die mit (Ind H4)2ZrCl2/MAO-Katalysator hergestellt worden sind.
    Notes: Ethylene/propylene copolymers (EPM) have been prepared by a liquid propylene suspension process, using homogeneous catalysts based on nonbridged zirconocenes and methylaluminoxane (MAO). When bis(η5-cyclopentadienyl)zirconium dichloride (Cp2ZrCl2), bis(η5-cyclopentadienyl) dimethyl zirconium (Cp2ZrMe2) and bis(η5-cyclopentadienyl), dibenzyl zirconium (Cp2ZrBz2) were used as catalyst components, EPM having low average molecular weight (MW) were in general obtained in low yield. On the contrary, a very large improvement of productivity and MW was observed when bis(η5-indenyl)zirconium dichloride (Ind2ZrCl2) and bis(η5-indenyl) dimethyl zirconium (Ind2ZrMe2) as well as bis(η5-tetrahydroindenyl)zirconium dichloride [(IndH4)2ZrCI2] were employed in combination with MAO. In particular, this last catalytic system allowed one to obtain EPM with a narrower distribution of MW in addition to the above characteristics. Better performances, in terms of rheological and elastomeric properties, were also found for the crude and vulcanized samples prepared by (IndH4)2ZrCl2/MAO catalyst.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052290107
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  • 3
    Electronic Resource
    Electronic Resource
    The observation of a novel biphase behavior in thermotropic side chain polymers (1991)
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 12 (1991), S. 43-49 
    Details
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1991.030120109
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  • 4
    Electronic Resource
    Electronic Resource
    Optically active methacrylic polymers with pendant chiral and trans-azobenzene moieties connected to the main chain by diacyl hydrazide linkages (1993)
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 14 (1993), S. 771-778 
    Details
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1993.030141207
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  • 5
    Electronic Resource
    Electronic Resource
    Mesomorphism  -  structure relationships in polyesters based on twin p-oxybenzoate mesogens (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 1655-1662 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Three homologous series of semiflexible polyesters constituted by twin spaced p-oxybenzoyl diads were studied with respect to their mesomorphic behaviour as a function of the relative length of the two different spacers [oligo(oxyethylene) and polymethylene] connected in an alternating fashion in the repeating unit. Within each series the oligo(oxyethylene) segment was maintained constant (n = 2, 3, 4), whereas the polymethylene segment varied in steps of one methylene unit from pentamethylene to decamethylene (m = 5 to 10). Indications are gained of how the parity of both ether and hydrocarbon spacers may affect the phase diagrams of the samples. The parity of the oligo(oxyethylene) segments appears in particular very effective in maximizing the orientational correlation between the mesogenic p-oxybenzoyl diads.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900717
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  • 6
    Electronic Resource
    Electronic Resource
    Chiral liquid-crystalline poly(ester/β-sulfoxide)s by asymmetric oxidation of prochiral nematic poly(ester/β-sulfide)sPresented in part at the American Chemical Society Meeting, Miami Beach, FL, USA, September 10-15, 19896. (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 2787-2793 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A new class of prochiral liquid-crystalline poly(ester/β-sulfide)s 2 and 3 containing the —S—C6H4—S— group was prepared, which were then asymmetrically oxidized to chiral liquidcrystalline poly(ester/β-sulfoxide)s 4 and 5 comprising the \documentclass{article}\pagestyle{empty}\begin{document}$\hbox{---} \mathop {\rm S}\limits^ * \left( {\rm O} \right)\hbox{---} {\rm C}_6 {\rm H}_4 \hbox{---} \mathop {\rm S}\limits^ * \left( {\rm O} \right)\hbox{---}$\end{document} group. A chiral 2-sulfonyloxaziridine 6 was used as the asymmetric oxidant and the reaction is highly chemoselective with quantitative yield. A 13C NMR analysis of a model poly(ester/β-sulfoxide) 8 is performed, which allows to evaluate the asymmetric induction and the enantiomeric excess for the asymmetric oxidation product. While the parent polymers 2 and 3 are nematic, the chiral modified polymers 4 and 5 are cholesteric.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021911127
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  • 7
    Electronic Resource
    Electronic Resource
    Optically active polymers containing side-chain azobenzene moieties: Photochromic and photoresponsive behavior of copolymers of N-(4-azobenzene) maleimide with (-)-menthyl vinyl ether and (+) (S)-2-methylbutyl vinyl ether (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2849-2857 
    Details
    ISSN: 0887-624X
    Keywords: photochromic chiral polymers ; photoresponsive polymers ; azobenzene-containing polymers ; N-(4-azobenzene) maleimide ; (-)-menthyl vinyl ether ; (S)-2-methylbutyl vinyl ether ; N-(4-azobenzene) maleamic acid ; N-(4-azobenzene) succinimide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochromic behavior and photoisomerization kinetics of optically active copolymers of trans-N-(4-azobenzene) maleimide (ABM) with (-) -menthyl vinyl ether (MtVE) and (+) (S) -2-methylbutyl vinyl ether were studied by UV spectroscopy under irradiation at 348 nm. The resulting data have been compared with those of the corresponding copolymers containing also trans-N-(4-azobenzene) maleamic acid co-units as well as of low molecular weight model compounds. The photoresponsive behavior has been also investigated by circular dichroism measurements at various extents of photoisomerization. The results are discussed in terms of structural requirements of the macromolecules. © 1994 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321506
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  • 8
    Electronic Resource
    Electronic Resource
    Sulfur-containing optically active polymers. V. Synthesis and chiroptical properties of optically active poly(γ-ketosulfide)s prepared by polyaddition of 1,3-dimercaptobenzene to 4,4-dimethyl-2,5-cyclohexadien-1-one or to trans, trans-2,5-heptadien-3-one in the presence of chiral amines (1996)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 2999-3013 
    Details
    ISSN: 0887-624X
    Keywords: optically active poly(γ-ketosulfide)s ; cinchona and ephedra alkaloids ; asymmetric polyaddition ; induced optical activity ; circular dichroism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Optically active poly(γ-ketosulfide)s having the asymmetric centers disposed along the main chain have been prepared by step polyaddition of 1,3-dimercaptobenzene to 4,4-dimethyl-2,5-cyclohexadiene-1-one, or to trans, trans-2,5-heptadiene-3-one, in the presence of catalytic amounts of chiral amines. The extent of asymmetric induction on the resulting polymeric product is found to be higher when the alicyclic ketone reagent is employed and is enhanced by lowering the catalyst concentration. The comparison of stereochemical features and chiroptical properties of appropriate low molecular weight analogues with those of the polymeric derivatives indicates that a comparable asymmetric induction occurs in polymers and model compounds, and that the former systems do not display appreciable evidence of ordered secondary structures, in agreement with a low stereoregularity degree along the macromolecular backbone. © 1996 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Optically active polymers containing side-chain photochromic moieties: Synthesis and chiroptical properties of copolymers of trans-4-(phenylazo)-1-naphthyl acrylate and trans-4-(1-naphthylazo)-phenyl acrylate with (—)-menthyl acrylate (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1159-1168 
    Details
    ISSN: 0887-624X
    Keywords: optically active copolymers ; photochromic polymers ; trans-4-(phenylazo)-1-naphthyl acrylate ; trans-4-(1-naphthylazo)-phenyl acrylate ; (—)-menthyl acrylate ; circular dichroism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of photochromic optically active copolymers from trans-4-(phenylazo)-1-naphthyl acrylate (PANA), or trans-4-(1-naphthylazo)-phenyl acrylate (NAPA), and (-)-menthyl acrylate (MtA) is described. The copolymers prepared, having different contents of trans-phenylazonaphthalene moieties, have been characterized by IR, 1H-NMR, UV, and GPC techniques. The chiroptical properties have been investigated by circular dichroism (CD) and the induced optical activity on the side-chain trans-phenylazonaphthalene chromophores discussed in terms of different conformational situations of the macromolecules in both the copolymer series. © 1994 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080320618
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  • 10
    Electronic Resource
    Electronic Resource
    Recent advances on photosensitive polymers: Polymeric photoinitiators (1996)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 7 (1996), S. 379-384 
    Details
    ISSN: 1042-7147
    Keywords: polymeric photoinitiators ; UV cure of clear and pigmented acrylic coatings ; benzoin methyl ether photoinitiators ; acyldiphenylphosphinoxide photoinitiators ; thioxanthone/α-morpholino acetophenone photoreactive systems ; photosensitizer/photoinitiator interactions ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This overview deals with recent developments on structure - activity relationships in polymeric photoinitiators for UV curable coatings. In particular, polymeric systems bearing side-chain benzoin methyl ether moieties are examined and the effect on the photoinitiation activity discussed in connection with the different anchorage positions of the photosensitive group to the polymer backbone. In addition, novel polymeric photoinitiators based on acyldiphenylphosphinoxide moieties are discribed and their photoinitiation activity related to the nature of the acyl group in the photoreactive molecule. Finally, polymeric systems having pendant thioxanthone and α-morpholino acetophenone moieties in the same macromolecule that are able to behave as photosensitizing and photoinitiating species, respectively, are reported. The much higher photoinitiation activity found for the above copolymers, compared with the mixtures of the corresponding low molecular weight analogs, is interpreted in terms of excitation energy transfer from the side-chain thioxanthone to α-morpholino acetophenone moieties, favored by their forced proximity along the polymer chain.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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