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Synthetic applications of non‐polymerizable monomers in living carbocationic polymerization
Author(s) -
Fodor Zs.,
Hadjikyriacou S.,
Li D.,
Takacs A.,
Faust R.
Publication year - 1995
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19950950107
Subject(s) - monomer , polymerization , cationic polymerization , polymer chemistry , living anionic polymerization , living polymerization , materials science , polymer science , chemical engineering , photopolymer , chemistry , radical polymerization , polymer , composite material , engineering
The foundation and methodology of using highly reactive but non‐polymerizable monomers in living cationic polymerizations is introduced. The chemistry and kinetics of 1,1‐diphenylethylene (DPE) addition to living polyisobutylene (PIB) in methyl chloride/n‐hexanes 40/60 v/v at −80°C is reported. Monoaddition occurred even when large excess of 1,1‐diphenylethylene was used. The methanol quenched polymer of the DPE capped PIB carried ‐OCH 3 functionality exclusively, suggesting that the diphenyl alkyl chain‐ends are completely ionized, which was confirmed by conductivity studies. By in‐situ functionalization using soft nucleophiles a variety of functional groups were obtained, most notably ester upon reaction with silyl ketene acetal. It was found that the diphenyl carbenium ion is an efficient initiating species for the polymerization of reactive monomers such as vinyl ethers and α‐methylstyrene. The synthesis of PIB based block copolymers was accomplished by sequential monomer addition, using para‐methylstyrene, α‐methylstyrene or isobutyl vinyl ether as the second monomer. It involved capping with DPE, followed by tailoring the Lewis acidity to the reactivity of the second monomer by the addition of titanium(IV) alkoxide, by replacing the Lewis acid with a weaker one or by the use of a common ion salt. PIB‐b‐PMMA was obtained by the combination of living cationic and group transfer (GTP) polymerizations.