ON GRADUAL DOSAGE OF THE INITIATOR IN THE SUSPENSION POLYMERIZATION OF VINYL-CHLORIDE

Initiator dosage in the solid phase during the suspension polymerization of vinyl chloride has been investigated with the use of a special apparatus developed for this purpose. Results are reported on a series of polymerizations in which the initiator was divided in various ratios between the starting and additional quantities, added either in one dose or repeatedly to the reaction mixture at various reaction times. Discussed is the kinetic course of polymerization and the effect of dosage on the rate of reaction heat release. It is found for the system used that a suitable dosage regime allows the total amount of the initiator to be reduced by as much as 15 percent, while the yield and the reaction time corresponding to the standard polymerization procedure remain unchanged.