BLENDS OF CAPROLACTAM CAPROLACTONE COPOLYMERS AND CHLORINATED POLYMERS/

The phase behaviour of blends of chlorinated polyethylene, polyvinyl c hloride (PVC) and chlorinated PVC with random copolymers of caprolacto ne and caprolactam has been investigated and the results correlated wi th a binary interaction model. The known miscibility of polycaprolacto ne in the chlorinated polymers is not compromised until a relatively h igh lactam content in the copolymer is attained. The incorporation of segmental interaction parameters, derived from separate studies involv ing polyamides, polyesters and their copolymers, has provided an estim ate of the unknown parameters. Using only six parameters to account fo r experimental data has provided moderate success; however, it is clea r that the representation of the chlorinated polymers, as pure copolym ers of methylene (-CH2-) and chlorine containing (-CHCl-) segments, is not sufficient to describe those blends. The reasons for this have be en discussed in terms of the influence of configuration of species upo n segmental interactions. Exploratory calculations are also presented depicting highly unfavourable interactions between aliphatic polyamide s and chlorinated polymers and to describe how the window of miscibili ty in blends of the latter with semi-aromatic polyesters is affected b y the methylene content of the polyester. (C) 1997 Elsevier Science Lt d.