Grafting on Polyvinylchloride in Suspension Using Phase Transfer

Abstract

Cationic grafting on polyvinylchloride (PVC) in solution was described by Kennedy et al. (1). The grafted polymers consisted of a PVC backbone with polyisobutylene, butyl rubber or polytetrahydrofuran (PTHF) branches. Catalysts such as di- or tri-alkyl aluminum halides or silver triflate, AgOSO₂CF₃, were used to achieve the grafting. It was assumed that the above grafting will improve the mechanical properties of PVC. For example, it was found that addition of PTHF to standard recipes of PVC leads to resins with high impact strength and good resistance to discoloration (2,3). The advantage of grafting on the PVC instead of just mixing the additives is very clear. In the former case the added material remains bonded to the polymer chain. In the latter one, the added material may diffuse out through the polymer matrix. Therefore, by using the right functional groups one can produce internally plasticized polymer or if the functional group attached to the polymer is a stabilizer, the grafted polymer will behave like internally stabilized one.