The precipitation polymerization of acrylonitrile (AN) was carried out in a mixture solution of dimethyl sulfoxide (DMSO) and water at 50~65℃ using α,α'-azobisisobutyronitrile (AIBN) as an initiator. The increased molecular weight polyacrylonitrile (PAN) was prepared with increasing the H2O/DMSO ratio from 10/90 to 80/20. The viscosity average molecular weight of H2O/DMSO solvent was 4.4 times larger than that of H2O/DMF solvent, and precipitation polymerization was accelerlated due to the far decreased chain transfer effect of DMSO. Based on the experimental results, the increased PAN molecular weight was regarded as the summation of two mechanisms: i) particle-particle aggregation and ii) particle-radical attachment. The theoretical equation derived from the mechanisms was well coincided with the experimental results showing the linear relationship between the viscosity average molecular weight and the H2O/DMSO ratio.

• Jing Zhang(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology)
• Fengjing Bu(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology)
• Yongqiang Dai(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology)
• Liwei Xue(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology)
• Zhixian Xu(Dept. of Chemistry and Chemical Engineering, Anyang Normal University)
• Seung-Kon Ryu(Dept. of Chemical Engineering, Chungnam National University)
• Riguang Jin(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology)