摘要
研究了氯乙烯 ( VC)与多种 N -取代马来酰亚胺的溶液共聚合 ,求得各对单体的竞聚率 .结果表明 ,各种马来酰亚胺的竞聚率都远高于 VC的竞聚率 ,即 N -取代马来酰亚胺单体的活性均比 VC单体活性高 .计算得到 N-取代马来酰亚胺 Q和 e值 .由于苯环的共轭效应 ,N-苯基及 N-取代苯基马来酰亚胺具有较大的Q值 .各对单体的 e值差别较大 ,表明有形成交替共聚物的倾向 .此外 ,还考察了聚合过程中共聚物组成的变化 。
Radical copolymerization of vinyl chloride(VC) with N-substituted maleimide were conducted in tetrahydrofuran at 60 ℃ with AIBN as initiator. Based on the copolymer composition and monomer composition, the copolymerization parameters(r 1, r 2, Q and e) of each monomer pair were determined. The reactivity ratios of N-substituted maleimide monomers were all larger than that of VC, indicating that these monomers were more active. The effects of substituted groups on reactivity ratios were also discussed, and N-substituted maleimide monomer had a larger Q value than that of VC, especially for phenyl substituted maleimide monomer. It was believed that this phenomenon was related to the conjugated effect of phenyl group in N-substituted maleimide. The location of substituent on phenyl would influence Q value of N-substituted phenyl maleimide monomer. para-Substituent(i.e. p-ClPMI and p-MPMI) phenyl maleimide has a large Q value than that of ortho- and meta-substituted phenyl maleimides. In addition, there is a larger difference between e 1 and e 2, which means the large alternating tendency of the copolymerization of N-substituted maleimide with VC. The copolymer compositions for VC/N-substituted maleimide solution copolymerization varied greatly with conversion, especially for small N-substituted maleimide feed ratios. Subsequently, recurrence method deduced from Mayo-Lewis was used for predicting the change of copolymer composition with conversion. In addition, this method is also used to calculate the critical weight [(x w) c] conversion for VC/N-substituted maleimide copolymerization systems at different VC monomer feed fractions.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2004年第10期1962-1965,共4页
Chemical Journal of Chinese Universities
基金
国家教育部博士学科点专项基金 (批准号 :95 3 3 5 0 4)资助
