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  • Polymer and Materials Science  (28)
  • nonlinear optical polymers  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Polymers degradable under environmental conditions through end-modification of poly(α-methylstyrene) derivatives (1997)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 247 (1997), S. 163-178 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: To induce degradabilities in polymers in response to environmental conditions, the end-modification reactions of poly(α-methylstyrene) derivatives were carried out. When diphenylphosphine chloride was used as a modifier for the living end of para-substituted PMS, the coupling efficiency was ca. 50%. 2-Phenylallyl halide derivatives such as 2-phenylallyl bromide, 2-(4-tolyl)allyl bromide, and α-trifluoromethylstyrene were found to be suitable end-modification agents. For example, ω-2-phenylallyl PMS was prepared with almost quantitative functionality by the reaction of the living PMS with 2-phenylallyl bromide. In a similar way, ω-3,3-difluoro-2-phenylallyl and ω-2-(4-tolyl)allyl PMS derivatives were synthesized. Based on thermogravimetric analysis, onset of the degradation temperature of the end-modified PMS derivatives decreased in the following order: ω-hydrogen- 〉 ω-3,3-difluoro-2-phenylallyl- 〉 ω-2-phenylallyl- 〉 ω-2-(4-tolyl)allyl-PMS. Actually, the onset temperature of ω-2-(4-tolyl)allyl-PMS derivatives was 50°C lower than that of ω-H-PMS derivatives. These results indicate that the active species is produced effectively at the end unsaturated bond, which initiates the depolymerization of the polymer at rather low temperatures. Ionic degradation of these polymers was also investigated using butyllithium as an anionic initiator and methanesulfonic acid as a cationic initiator. Tendencies similar to the thermal degradation were observed. Therefore, it is concluded that a 2-phenylallyl substituent at the end of the PMS chain induces effective degradation through several mechanisms such as radical, anionic and cationic depolymerization reactions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1997.052470111
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  • 2
    Electronic Resource
    Electronic Resource
    A novel synthesis of polystyrene macromonomers (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 1583-1591 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Lithium diisopropylamide (2) was found to undergo a metalation reaction with 4-methylstyrene (1) to form 4-vinylbenzyllithium (3), but to induce neither addition reaction nor vinyl polymerization. The equilibrium constant between 2 and 3 in THF was calculated to be 0,54 at 20°C. The 4-vinylbenzyllithium formed initiates the polymerization of styrene derivatives to form oligomers. The resulting oligomers have a polymerizable vinyl group at the chain end quantitatively and can be regarded as a “macromonomer”. Synthesis of polystyrene, having a primary amino group at the chain end, was carried out through the reaction of polystyrene macromonomer with N-methylethylenediamine. More than 97% of polystyrene were aminated within 6 h reaction.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021870702
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  • 3
    Electronic Resource
    Electronic Resource
    Studies on functional diene oligomers with an amino end group, 2Part 1: cf.1 b.. Reaction mechanism of the isoprene oligomerization (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 186 (1985), S. 1335-1350 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Lithium diisopropylamide, in the presence of diisopropylamine, initiates the polymerization of isoprene to form oligomers having one diisopropylamino end group. These oligomers 1 a, formed in the early stages of the reaction, are considered to carry out the chain termination (or metalation) reaction. Results of mechanistic studies of the chain termination (or metalation) reaction in isoprene oligomerization in the presence of various types of allylamine homologues, as low molecular weight model compounds for 1 a are presented. The presence of a cis-methyl group with respect to the amino methylene group was found to be essential for the low molecular weight model compounds to exhibit large reactivity in the chain transfer reaction. Oligomers with amino end groups neither have to possess a cis-methyl group nor an allylamine structure to be active. A number of results showed that the driving force for the metalation reaction of oligomers with amino end groups is different in nature from that of the lowmolecular-weight allylamine homologues. A possible mechanism for the metalation reaction of these oligomers is discussed in terms of a hydrophobic interaction with the growing chain.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.021860701
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  • 4
    Electronic Resource
    Electronic Resource
    Studies on functional diene oligomers with an amino end group, 3Part 2: cf.6.. Synthesis of oligoisoprenes containing a secondary amino end group (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 53-60 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Lithium monoalkylamide, in the presence of monoalkylamine, was found to initiate the polymerization of isoprene to form oligoisoprenes. The molecular weight distribution of products formed in the lithium isobutylamide initiated isoprene oligomerization strongly depends on the initial mole ratio [Isoprene]0/[Amine]0/[Amide]0; with an initial mole ratio of 60/1/8, oligomers with a number-average molecular weight of about 800 were obtained. The presence of N,N,N′,N′-tetramethylethylenediamine in the reaction system was found to be effective for the selective formation of secondary amino-ended oligoisoprenes.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900107
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  • 5
    Electronic Resource
    Electronic Resource
    Reactivities of 4-trimethylsilylmethylstyrene and 4-bis(trimethylsilyl)methylstyrene (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 1855-1866 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 4-Trimethylsilylmethylstyrene (1), and 4-bis(trimethylsilyl)methylstyrene (2) were synthesized and polymerized. The reactivities of 1 and 2 in free radical and nucleophilic reactions are discussed, referring to 1H NMR and UV spectral data. The absolute values of the negative e- values were found to be higher than those of styrene and other styrene derivatives such as 4-methylstyrene. The reactivities of these monomers toward nucleophilic reagents are lower than those of other styrenes. From these investigations it was concluded that the trimethylsilylmethyl group, located at 4-position of vinylbenzene, exhibits an electron donating effect. As anticipated, the effect of the bis(trimethylsilyl)methyl group is larger than that of the trimethylsilylmethyl group. AM1 calculations showed that the effect is attributable to the σ-π-hyperconjugation between the Si—C σ-bond and the π-electron system of the phenyl ring. The larger effect of 2 as compared with 1 may be explained by additional σ-π-hyperconjugation between the second C—Si bond in horizontal position and the phenyl π-orbital in addition to the σ-π-hyperconjugation of the first C—Si bond in vertical position.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900811
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  • 6
    Electronic Resource
    Electronic Resource
    Soluble poly(divinylbenzene): Reaction mechanism for the anionic polymerization of divinylbenzene with lithium diisopropylamide as catalystDedicated to Prof. Dr. Dr. h. c. mult. G. V. Shulz on the occasion of his 80th birthday (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 23-37 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This paper presents results of the studies on the mechanism of initiation, propagation and chain transfer reactions in the recently found polymerization of 1,4- and/or 1,3-divinylbenzene (DVB), initiated with lithium diisopropylamide/diisopropylamine. Initiation was confirmed to take place by addition reaction of the alkylamino group to the DVB molecule. The population of the triad tacticity of the soluble poly(DVB) suggested the steric course of the polymerization to proceed according to Bernoullian statistics with respect to the diad placements, m and r. The chain transfer reaction was found to take place via the free amine, the chain transfer reactivity of a primary amine being higher than that of a secondary amine. Comparative studies on the reactivity and selectivity of sodium diisopropylamide toward styrene and DVB were also carried out with respect to lithium diisopropylamide as reference.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021870103
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesis of novel functional styrene monomers having trimethylsilyl and hydroxyalkyl groups by the reaction between 4-vinylbenzyllithium derivatives and oxiranes (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 2297-2308 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: New synthetic routes for styrene derivatives having both trimethylsilyl and hydroxyalkyl groups were investigated. Reactions between oxirane (5a) and chemical species present in an equilibrium system resulting from 4-(trimethylsilylmethyl)styrene (1s) and lithium diisopropylamide (2) in tetrahydrofuran give an addition product (8a) between 2 and 5a preferentially. By using alkyl-substituted oxiranes such as ethyloxirane (5c) and tert-butyloxirane (5e), a 1 : 1 addition reaction of 1s with the oxiranes takes place predominantly to form 1-alkyl-3-trimethylsilyl-3-p-vinyl-phenyl-1-propanol (8) homologues. From results of studies on the reaction between 2 and several oxiranes, it was concluded that the selective formation of 8 homologues was attained by suppression of reactions between oxirane and 2 owing to steric hindrance between alkyl substituents of oxirane and isopropyl groups of 2. The reactivity of 8 in polymerization reaction was also estimated on the basis of spectroscopic measurements. 8 was found to have a reactivity similar to that of 4-(trimethylsilylmethyl)styrene (1s).
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021911008
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  • 8
    Electronic Resource
    Electronic Resource
    Novel organosilicon-containing polymers for an oxygen permselective membrane (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 2103-2110 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Synthesis and gas permeation measurements of several types of polymers from methylstyrene derivatives containing mono-and bis(trialkylsilyl) group(s) were carried out. Upon radical homo-and co-polymerization of silicon-containing monomers high-molecular-weight polymers were obtained. Results from gas permeation measurements showed that these types of silicon-containing polymers exhibit fairly high oxygen permselectivity (ratio of oxygen and nitrogen permeation coefficients PO2/PN2 = 3,1 - 4,6), keeping the oxygen permeation coefficients (PO2) in the range of between 1,4 · 10-9 and 4,5·10-9 cm3 (STP) · cm · cm-2 · s-1 · cmHg-1. From time lag measurements, it was found that permeation coefficients are dependent on the solubility of gases in the membranes rather than on diffusivity. Actually, the oxygen solubility coefficients increase with increasing silicon content in the polymers. Permselectivity of oxygen against nitrogen is governed by polymer constitution rather than by silicon content.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021910913
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  • 9
    Electronic Resource
    Electronic Resource
    Reactivity in radical and anionic copolymerizations of 4-(trimethylsilyl)styrene. Synthesis of soluble poly{(1,4-divinylbenzene)-co-[4-(trimethylsilyl)styrene]} (1992)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 193 (1992), S. 1633-1641 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Radical copolymerization of 4-(trimethylsilyl)styrene (TMSS) with styrene were carried out to estimate the reactivity of TMSS. The monomer reactivity ratios r1 and r2 in the radical copolymerization of TMSS (M1) with styrene (M2) were evaluated as 0,28 and 0,48, respectively. The value r1 · r2 (= 0,13) being smaller than unity indicates that the trimethylsilyl group at para position behaves as an electron-withdrawing substituent. Reactions of lithium diethylamide with TMSS in the presence of diethylamine, gave the 1:1 addition product 1-[2-(N,N-diethylamino)-ethyl]-4-(trimethylsilyl)benzene. Kinetic analysis showed that the second-order rate constant (k) for this addition reaction is 34,4 · 10-4 dm3 · mol-1 · s-1, which is by a factor of 2 larger than that for the reaction with styrene (k = 16,0 · 10-4 dm3 · mol-1 · s-1). The fact is also compatible with the above consideration for the r1 · r2 values. Lithium diisopropylamide initiated anionic copolymerizations of TMSS with 1,4-divinylbenzene (DVB) were also examined. The polymerizations proceed smoothly without any gel formation and the resulting copolymers are soluble in various common solvents such as benszene, tetrahydrofuran, chloroform, etc. Thus, novel organosilicon-containing polymers having appropriate amounts of reactive pendent vinyl groups are easily synthesized.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1992.021930707
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  • 10
    Electronic Resource
    Electronic Resource
    Studies of functional diene oligomers with an amino end group, 1. Synthesis of functional oligomers of isoprene with one diisopropylamino end group (1983)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 184 (1983), S. 737-744 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Lithium diisopropylamide in the presence of diisopropylamine initiates the polymerization of isoprene to form oligomers with one diisopropylamino end group. The molecular weight of the oligomers formed is strongly dependent on the mole ratio diisopropylamine/lithium diisopropylamide. For instance, more than 70% of the oligomers obtained have an average molecular weight of 1 000, provided the reaction is run with an initial mole ratio 1:2 of amine to amide. Reactivities of several allylamine derivatives including the oligomers with amino end groups were studied in regard to their ability as chain transfer agents in the anionic polymerization of isoprene. According to the 1H NMR analysis, these oligomers contain 90% 1,4- and 10% 3,4-enchainments.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1983.021840408
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