Polymerization of vinyl acetate with styrene and α-methylstyrene under high oxygen pressure

Abstract

The polymerization of vinyl acetate with styrene and a-methyl styrene of various compositions has been studied by the free radical-initiated oxidative polymerization. The compositions of the resultant polymers obtained from ¹H and ¹³C{H¹} NMR spectra have been utilized to determine the reactivity ratios of the monomers. The reactivity ratios reflect the tendencies of the two monomers towards consecutive homopolymerization. The NMR studies reveal irregularities in the chain due to the cleavage reactions of the propagating peroxide radical. The thermal degradation study by differential scanning calorimetry (DSC) supports alternating peroxide units in the polymer. The activation energy for the thermal degradation suggests that the degradation is controlled by the dissociation of the peroxide (-O-O-) bonds of the polymer.