According to kinetic mechanisms, liquid phase polymerization and solid phase polymerization
are different in acrylonitrile (AN) polymerization, and so the relationship between the
contribution ratio and molecular weight distribution (MWD) was obtained through theoretic
analysis. The precipitation homopolymerization of AN was carried out in a mixture solution
of dimethyl sulfoxide (DMSO) and water at 50~65oC using α,α’-azobisisobutyronitrile as
an initiator. The contribution ratio decreased and approached 0; the MWD also decreased
and approached 2 with the increase of the H2O/DMSO ratio from 10/90 to 90/10. The
experimental data were found to coincide well with the theoretical equation derived from
the mechanisms.