부산대학교 도서관

Copolymerization of 1,3-dioxolane(DOL) and isoprene(Ip) by BF3·Et2O has been studied, particularly laying stress on the microstructure of the products. The diad fractions determined by NMR analysis have indicated that both monomer units are distributed randomly in the copolymer chain. The loss of unsaturation (the fraction of saturated Ip units to total Ip units), which was generally observed in cationically prepared Ip homopolymers, diminished with increasing DOL fraction and became practically negligible in the copolymers rich in DOL units. The structure of Ip units in the copolymer was also found to depend on the composition, namely, the fraction of the 1,4-structure, which was prevailing in Ip homopolymers prepared by the cationic initiator, decreased markedly with increasing DOL fraction in the copolymer.