1-Chloro-1,3-butadiene Copolymers. III. Reactivity of 1-Chloro-1,3-butadiene in Radical Copolymerizations

Abstract

Radical copolymerizations of 1-chloro-1,3-butadiene (CB) were carried out with styrene (St), 1,3-butadiene (Bd), or chloroprene (Cp) in toluene at 70 °C by AIBN. The monomer reactivity ratios are found as follows: rCB=1.21±0.10, rSt=0.10±0.03; rCB=0.27±0.02, rBd=0.56±0.03. Copolymerization of CB and Cp showed CB was much less reactive than Cp. The Q and e values of CB were calculated to be 3.13 and +0.65, respectively. 1H NMR and IR of poly(CB-co-St) showed 60% of CB units are of 1,4-configuration and the rest 3,4-configuration.

1-Chloro-1,3-butadiene Copolymers VI. Structure of the Diene Unit and Monomer Sequence Distribution in the Copolymer with Styrene

“…As the CB content increases, the 1,4-structure content remains constant within the experimental error of 1 H NMR measurement, and the average value of I ,4-structure content (58± 3%) is in good agreement with the reported constant value (59± 5%) for poly(CBco-St)s obtained by solution polymerization. 7 In spite of the presence of phenyl groups of St units, their effect on the chemical shifts was not observed in the present experiment.…”

“…Our experimental results are difficult to reconcile with their observations; i.e., the degrees of the reactions of chlorine in poly(CB-co-1,3-butadiene) with amine, 4 sodium diethyldithiocarbamate 5 or water (hydrolysis) 6 had a limiting value at ca. 60%, and 1 H NMR of poly(CB-co-St) obtained by solution polymerization 7 showed the presence of ca. 60% in the 1,4 structure and the rest in the 3,4 configuration.…”