Study On Aqueous Precipitation Polymerization Process For Synthesis Of Polyacrylonitrile Containing High Vinyl Acetate Content

A continuous stirred tank reactor (CSTR) at10L scale had been established in our lab. Aqueous precipitation terpolymerization of acrylonitrile (AN)/vinyl acetate (VAC)/sodium methacrylic sulfonate (MAS) was carried out with this apparatus using sodium chlorate (SC)/sodium bisulfite (SBS) as redox initiator. The repetition of the small-scale reactor for the synthesis of terpolymer was well demonstrated relative to the large-scale apparatus. Effects of the feeding ratio of monomers, pH value, mean residing time, oxidant concentration, and the amount of chain transfer agent on the VAC content of terpolymer, polymerization conversion, molecular weight and the morphology of the polymer particle were investigated in detail。 It was found that the polymer conversion strongly impacted on the controllability of the process while the other process parameters could be adjusted to achieve the terpolymer with high VAC content. Based on large numbers of experiments, an optimized process for the preparation of high VAC content-containing terpolymer was proposed.