Rheology and plasticization of polyvinyl chloride

Abstract

The behaviour of polyvinyl chloride in the range of temperatures from 77°C to 230°C is characterized by the persistence of a slight amount of crystallinity, which gives rise to very peculiar rheological properties. In particular flow takes place partially through particle slippage, which predominates, with respect to molecular deformation, the lower the temperature and the higher the molecular weight and the crystallinity. The flow behaviour may change appreciably with shearing time and with thermal history. Viscous heat generation must be taken into account, even at relatively low shears. The molecular weight dependence of viscosity and relaxation time is anomalous for both rigid and plasticized samples. For the latter, the composition dependence of the glass transition temperature appears to be in line with predictions based on free volume concepts. © 1971, Walter de Gruyter. All rights reserved.