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%.
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.
采用差示扫描量热法,研究了丙烯腈(AN)/丙烯酸(AA)共聚物在空气中的低温热解反应,利用K iss inger方法,计算了AN/AA共聚物热解反应的表观活化能,讨论了不同聚合工艺对共聚物热解反应表观活化能的影响。结果表明,随混合溶剂中二甲基亚砜含量的增加,共聚物热解反应表观活化能增加;随共聚单体AA含量的增加,共聚物热解反应表观活化能降低;当AA与AN质量配比高于5/95后,共聚物热解反应表观活化能变化不大;随反应温度增加,共聚物热解反应表观活化能增加。
