PREPARATION AND APPLICATION OF LOW-MOLECULAR-WEIGHT POLY(VINYL CHLORIDE) .4. PREPARATION AND CHARACTERISTICS OF POLY(VINYL CHLORIDE) WITH BROAD MOLECULAR-WEIGHT DISTRIBUTION

Poly (vinyl chloride) (PVC) with a broad molecular weight distribution (BMD-PVC) was prepared by suspension polymerization in the presence of PVC with relatively lower molecular weight (LMW-PVC), which was prepared by suspension polymerization in the presence of 2-mercaptoethanol as a chain-transfer agent. It is elucidated using porosity measurement, scanning electron microscopy (SEM), and energy dispersion X-ray microscopy (EDXM) that the resultant BMD-PVC grains have an interesting internal structure at the level of primary particles. Discoloration time and fusion time of the BMD-PVC was studied. Discoloration time and fusion time of BMD-PVC is particularly dependent on the polymerization degree (Pw) of LMW-PVC and LMW-PVC content in the BMD-PVC samples. (C) 1994 John Wiley & Sons, Inc.