Studies on composition of copolymers in vinylidene chloride-acrylonitrile suspension copolymerization

In VDC-AN suspension copolymerization, the effect of water solubility of AN on composition of both the monomers and the copolymer was studied. The results showed that the composition of the copolymers was significantly different from the bulk model prediction, because AN was partially water soluble and it decreased the AN content in organic phase. In this work for exact calculation of the composition of VDC-AN copolymer,it was supposed that transfers of the disserved AN to the organic phase were much faster than polymerization, and AN phase partition in VDC/water system was nearly balanceable. The Marker formula describing AN phase partition between VDC and water was used in the correction of AN content in organic phase,and then the composition of VDC-AN copolymers was calculated with the Mayo-Lewis formula using the reactivity ratio values from the bulk polymerization literature. It was found that the calculated data agree with the experimental results.