摘要:

AbstractA study has been made of the function of X and R on the interfacial synthesis of poly(stannylalkylenediamines) of the below form:Molecular weight and yield are constant as X is varied. The molecular weight of the polymer increases as the steric hindrance of R decreases. Possible reaction mechanisms are discussed.

ISSN:0025-116X    

DOI:10.1002/macp.1971.021410121

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractTo clear up the detailed mechanism of the alternating copolymerization of styrene (St) and maleic anhydride (MAn) concerning the initiation species, the propagation species, the tendency of the chain transfer reaction as well as the directional tendency of the reaction between copolymer radicals and monomer complexes, the role of the charge transfer complexes, characterization of end groups and additional donor effects were examined.The equilibrium constant of the St/MAn (1 : 1) complex was determined to be 0.31 by NMR spectroscopy, that suggested considerable amounts of complexes existing in the system. As expected, a small quantity of initiator (14C‐azobisisobutyronitrile (AIBN)) was incorporated into the St/MAn copolymer. Chlorine atoms were scarcely incorporated into the copolymer synthesized in CCl4with AIBN or benzoyl peroxide (BPO) as an initiator. Hence the copolymerization was considered to be induced only by attacke of initiator radicals to the monomer or the complexes, contrary to the usual conception of telomerization.When the electron donor monomer was added to the system, the terpolymerization could be treated as a copolymerization of the two complexes,i.e., St/MAn and Donor/MAn. By adding naphthalene the rate maximum point shifted from higher concentration of MAn to the equivalent concentration of St and MAn. Degradative chain transfer to N.N‐dimethylaniline was observed, confirming the existance of poly‐MAn radicals. It was suggested from these results that the charge transfer complex and uncomplexed MAn took part in the copolymerization of St and MAn. This was proved kinetically. The whole mechanism was disc

ISSN:0025-116X    

DOI:10.1002/macp.1971.021410122

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractÀ 25°C, la peroxydation du polystyrène est accompagnée d'une dégradation oxydante mise en évidence par la fragmentation des macromolécules sans période d'induction mesurable.L'étude cinétique de cette dégradation a été faite en amorçant les réactions d'oxydation du polymère par irradiation γ (60Co) de ses solutions dans le chloroforme. L'analyse des produits légers par chromatographie en phase gazeuse et la détermination de la cinétique de formation des coupures au hasard par viscosimétrie ont été réalisées simultanément sur les solutions irradiées.L'hypothèse de la production d'une molécule de styrène lors de la formation de chaque coupure, coupure qui résulterait de la décomposition monomoléculaire de radicaux peroxyles secondaires selon un mécanisme avec état de transition hexagonal, per

ISSN:0025-116X    

DOI:10.1002/macp.1971.021410123

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

ISSN:0025-116X    

DOI:10.1002/macp.1971.021410124

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

ISSN:0025-116X    

DOI:10.1002/macp.1971.021410125

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

ISSN:0025-116X    

DOI:10.1002/macp.1971.021410126

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY