A Study of Synthesis and Characteristic of Poly(Acrylonitrile-Methylacrylate-Vinylpyrrolidone) Initiated by 2,2' -Azobisisobutyronitrile in DMF Solution System

DMF 용액에서의 Acrylonitrile-Methylacrylate-Vinylpyrrolidone 3원 공중합체의 합성 및 특성 연구

This study is concerned with copolymerization of acrylonitrile (AN) with methylacrylate (MA), vinylpyrrolidone (VP) using the 2,2'-azobisisobutyronitrile (AIBN) initiator in dimethyl formamide (DMF) solution. In the free radical polymerization using DMF solution, the rate of polymerization is linearly increased with increasing monomer concentration. The extent of conversion is almost linearly increased with increasing polymerization time at the monomer concentrations of 27.67 wt%, 32.67 wt%, and 37.67 wt%, whereas an abrupt increase of the conversion rate is observed at higher monomer concentrations. In fact, the polymerization process at the monomer concentrations higher than 42.67 wt% was very difficult to control, because the extensive exothermic polymerization reaction accelerates the polymerization reaction. This indicates that an self-acceleration and irregular chain transfer reaction take place during polymerization. Thus, the number-average degree of polymerization is decreased with the monomer concentration. It was found that optimum concentration of monomer is 37.67 wt%. On the other hand, the limitting conversion and number-average degree of polymerization were increased with increasing VP content.