Syntheses and properties of ethylene sulphide-isobutylene sulphide copolymers and their unsaturated terpolymers

The synthesis with anionic catalysts and the characterization of ESIBS copolymer and ESIBSATE terpolymer are reported (ES, IBS, ATE and PS = ethylene sulphide, isobutylene sulphide, 3-allyloxy-1,2-epithiopropane and propylene sulphide respectively). For ESIBS copolymer with 35–55% ES, nearly amorphous structures, were obtained. Microstructures, investigated by ¹³C-NMR, have been compared with that of the ESPS copolymer; the ESIBS copolymer has greater blockiness than ESPS. Some preliminary results on the properties of ESIBSATE unsaturated terpolymer are also reported and compared with those of the known ESPSATE terpolymer. The good swelling values shown by the former are related to the possibility of obtaining amorphous structures with a high ES content.