In order to prepare a polymer solution for making carbon fibre precusor by wetspinning,solution polymerization of acrylonitrile ( A N) with itaconic acid ( I A) was carriedoutin D M S Ousing azobisisobutyronitrile ( A I B N) asinitiator. The effects of( A N+ I A) and A I B N concentration , A Nto I Aratio,temperature on conversion rate and molecular weightwere investigated . The polymerization ratein D M S O was 2 .6 time as fast at thatin D M F. The copolymers were characterized by I Rand N M Ranalysis.
The molecular weight of acrylonitrile/itaconic acid copolymer can be calculated from the intrinsic viscosities of the dilute reaction solutions directly, when the conversion was higher than 90% during the solution polymerization. Because of the sample treatment processes such as film preparing, washing, drying and redissolving were simplified, the analysis time was reduced substantially. The proposed method is more suitable for rapid analysis. The measurement error compared with common method of determination for the copolymer in DMSO by single point method was about 1%.
