Effects of poly(vinyl acetate) suspending agents on suspension polymerisation of vinyl chloride monomer

When partially hydrolysed poly(viny] acetate) (PVAc) is used as a suspending agent in the suspension polynicrisation oF vinyl chloride monomer, it has signiticant efFects on the morphology of lhe resulting poly(vinyl chloride) (PVC) particles. At the initial step of polymerisation, PVC molecules are grafted onto the molecules of the suspending agent forming a PVC-PVAe membrane. The properties of this nnembrane depend on the type of suspending agenl. lhe polymerisation temperature, the mixing efficiency, and other factors. The morphology of the growing PVC particles and the properties of lhe PVC resin obtained depend in turn on the characteristics of the membrane. A model has been developed relating to the connection between the polymerisation conditions and lhe characteristics of the suspending agenl on one hand, and on the PVC properties on the other hand. The model is based on an analysis of the characteristics of the PVC-PVAe membrane and their effect on PVC properties.