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Etude par résonance magnétique nucléaire des polychlorures de vinyle polymérisés par les systémes titanate de butyle–alcoyles‐aluminium
Author(s) -
Pham Q. T.,
Rocaniere P.,
Guyot A.
Publication year - 1970
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1970.070140516
Subject(s) - radical , chemistry , polymer chemistry , hydrogen atom abstraction , vinyl chloride , polymerization , chlorine , chloride , hydrogen chloride , photochemistry , polymer , organic chemistry , copolymer
NMR analysis of the chain ends of samples of poly(vinyl chloride) prepared using a Ti(OBu) 4 –alkylaluminum system in CCl 4 reveals that the mechanism of the formation of free radicals depends on whether the alkylaluminum used is chlorinated or not. In the first case, some of the radicals are reactive in the initiation step of the polymerization, while in the latter case theses radicals first undergo transfer to CCl 4 , then the CCl 3 · formed initiates the polymerization of vinyl chloride. The poly(vinyl chloride) radicals are chiefly stopped by transfer to CCl 4 (chlorine abstraction) or to alkylaluminum (hydrogen abstraction). In transfer reactions between growing radicals and alkylaluminum, the radicals formed have to react with CCl 4 before reinitiating the polymerization of vinyl chloride.