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  • 1
    Electronic Resource
    Electronic Resource
    Hydride transfer to stable carbenium salts (1983)
    Springer
    Polymer bulletin 10 (1983), S. 411-413 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The interaction between (C6H5)3CSbCl6, (C6H5)2CHSbCl6, (ClC6H4)3CSbCl6 and poly(ɛ-caprolactone), dimers of α-methyl-styrene and of 1,1-diphenylethylene is investigated. By the use of 1H-NMR spectroscopy it is found that hydride transfer proceeds to the stable salts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00262182
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  • 2
    Electronic Resource
    Electronic Resource
    Separation and characterization of ɛ-caprolactone oligomers by gel permeation chromatography (1985)
    Springer
    Polymer bulletin 13 (1985), S. 285-291 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary It is shown that the combined use of gel permeation chromatography and the isocyanate method of determination of hydroxyl end groups extends the possibilities for studying complex oligomer mixtures of ɛ-caprolactone. Oligomer mixtures of ɛ-caprolactone obtained by (C6H5)3CSbCl6 and by (C6H5)3CK are investigated. At initiation by both the initiators — the cationic and the anionic one — a covalent bond between the initiator and the polymer chain is formed. In the case of the initiation by (C6H5)3CK intramolecular transesterification proceeds which results in cyclic oligomers. At initiation by (C6H5)3CSbCl6 linear oligomers are formed. It is assumed that the ɛ-caprolactone polymerization by (C6H5)3CSbCl6 proceeds by alkyl-oxygen bond scission.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00254664
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  • 3
    Electronic Resource
    Electronic Resource
    Kinetik der Styrolpolymerisation mit BF3.(C2H5)20 in Gegenwart von π-Elektronen-Acceptoren (1977)
    Springer
    Colloid & polymer science 255 (1977), S. 809-809 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01664467
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  • 4
    Electronic Resource
    Electronic Resource
    Polymerization of cyclic acetals. I. Polymerization of 1,3,6-trioxacyclooctane and copolymerization with p-methoxystyrene (1987)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 2561-2568 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of 1,3,6-trioxacyclooctane initiated by trityl salts with various counterions in CH2Cl2 was investigated. The reaction mixtures and the isolated polymers were analyzed by GPC (double detection - IR and UV at 254 nm),1H-, and13C-NMR spectroscopy. In the early stage of polymerization only oligomers (mainly cyclic) were formed. With longer reaction times, linear polymers (yield 86-94%, M = 70,000-80,000) were obtained. The concentration of each individual oligomer passed through a maximum and decreased, reaching its equilibrium concentration. The time interval necessary to reach the maximum concentration increased with n. The total concentration of the oligomers was 0.2 mol L-1 regardless of the initiator used. Conditions for polymerization with virtually no termination were found. Addition of p-methoxystyrene to the “living” polyacetals resulted in block copolymers. GPC,1H- and 13C-NMR and acidolytic degradation were used to prove the formation of AB block copolymers. The reactive alkoxycarbenium growing species are responsible for the formation of block polyacetal-polymethoxystyrene copolymer.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1987.080250920
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  • 5
    Electronic Resource
    Electronic Resource
    Styrene-isoprene block copolymers. I. Synthesis and solution properties (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1107-1112 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers with a different degree of distribution of styrene and isoprene blocks are prepared by anionic polymerization. The products are characterized by means of 1H-NMR spectroscopy, GPC, viscometry, and light scattering. The results show that the copolymers are homogeneous in molecular weight and chain composition. In the investigated selective solvents, cyclohexane and base lubricating oil, and equilibrium exists between micelle aggregates and individual polymer coils. The influence of the copolymer structure on the micellization is more pronounced in cyclohexane.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1991.080290804
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  • 6
    Electronic Resource
    Electronic Resource
    Characteristics and initiation ability of 9-anthranylmethyl hexafluorophosphate (1986)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 3271-3277 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 9-Anthranylmethyl hexafluorophosphate-a stable primary carbenium salt-is prepared and characterized by UV, VIS, and NMR spectroscopy and by conductometric measurements in methylene chloride. 9-Anthranylmethyl hexafluorophosphate initiates the polymerization of vinyl and heterocyclic monomers. This initiator has higher reactivity than trityl and diphenylmethyl salts. The initiation mechanism of the polymerization of some monomers is investigated.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1986.080241211
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  • 7
    Electronic Resource
    Electronic Resource
    Polymerization of cyclic acetals. II. Synthesis of amphiphilic block copolymers (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 3145-3154 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The sequential copolymerization of 1,3,6-trioxacyclooctane (TOC) and 1,3-dioxolane (DOL) (B) with various vinyl monomers (A) was investigated. Under appropriate conditions amphiphilic block copolymers of the type AB and ABA were formed. The reaction mixtures and the isolated polymers were analyzed by GPC (double detection - IR and UV at 254 nm), IR, 1H-, and 13C-NMR spectroscopy. Block copolymers with chosen molecular weights and low polydispersity could be obtained only by sequential copolymerization of p-methoxystyrene on “living” TOC. In the polymerization of DOL with α-methylstyrene and i-butyl vinyl ether (IBVE) transfer reactions take place to a larger degree.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1990.080281120
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  • 8
    Electronic Resource
    Electronic Resource
    Interaction of triphenylmethyl salts with vinyl ethers (1987)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 1569-1577 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The initiation of isobutyl, n-butyl, ethyl, and 2-chloroethyl vinyl ethers polymerization by trityl ion salts was investigated. The oligomers formed and the reaction mixtures were analyzed by GPC and 1H-NMR spectroscopy. It is concluded that the initiation proceeds via two competing reactions. The addition of the initiator to the monomer is determined as usual by the electrophilicity of the former and the nucleophilicity of the latter. In order to realize initiation by hydride transfer it is necessary for the monomer to possess a hydrogen atom with hydride mobility and that the cation obtained is sufficiently stable. The relative part of these initiation reactions is determined.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1987.080250611
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  • 9
    Electronic Resource
    Electronic Resource
    Macromonomers from vinyl and cyclic monomers prepared by initiation with stable carbenium salts (1987)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 3283-3292 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The initiation of polymerization of α-methylstyrene and p-methoxystyrene with 9-anthranylmethyl salts proceeds by hydride transfer from the monomer to the initiator. As a result, macromonomers with a double bond as head group are formed. These products polymerize and copolymerize by radical and ionic mechanism leading to graft and block copolymers. Styrene and α-caprolactone polymerize with the same initiator by cationation of the monomer. In this case each macromonomer contains one photoreactive anthranylmethyl group which may photodimerize. As a result copolymers of the type A—A or A—B are produced.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1987.080251209
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  • 10
    Electronic Resource
    Electronic Resource
    Styrene-isoprene block copolymers. II. Hydrogenation and solution properties (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 3083-3090 
    Details
    ISSN: 0021-8995
    Keywords: 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 , Physics
    Notes: Styrene-isoprene block copolymers with a different degree of monomer distribution are hydrogenated with homogeneous catalysts. The products are characterized by means of IR and 1H-NMR spectroscopy, GPC, viscometry, and light scattering. Hydrogenation proceeds without destruction and selectively for olefinic unsaturation. The hydrogenated copolymers are homogeneous in molecular weights and chain composition. The influence of the copolymer structure on the solution properties in selective solvents is established. In cyclohexane an equilibrium between micelle associates and individual polymer coils, monomolecular micelles, or micelle aggregates are observed, depending on the type of the copolymer. The micellization in base-lubricating oil leads to micelle fractions with a different degree of association.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070421202
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