低分子量聚N-乙烯基甲酰胺-co-乙烯胺的合成

Synthesis of Poly( N-vinylformamide-co-vinylamine)with Low Molecular Weight

以N-乙烯基甲酰胺为单体,N,N-二甲基甲酰胺和乙酸乙酯为混合溶剂,偶氮二异丁腈为引发剂,十二硫醇为链转移剂,通过沉淀聚合法制备了低分子量的聚N-乙烯基甲酰胺。详细研究了单体质量分数、混合溶剂配比、引发剂用量、链转移剂用量、反应温度及反应时间对聚合反应的影响。在最佳聚合条件下,聚合物收率可达93.1%、聚合物的数均分子量（Mn）为2 975.2,PDI=2.64,且聚合残液可循环利用。然后将所得聚合物在酸性条件下水解,制备了不同胺化度的聚N-乙烯基甲酰胺-co-乙烯胺,产品的数均分子量为1 000~1 400,PDI为1.34~1.40。

Low molecular weight polymer of poly（ N-vinylformamide） was synthesized by precipitation polymerization in N,N-dimethyl formamide and ethyl acetate,using azobisisbutyronitrile as the free radical initiator and dodecyl mercaptan as the chain transfer agent. The influences of monomer mass fraction,component solvent ratio,initiator concentration,chain transfer agent concentration,reaction temperature and time on the precipitation polymerization were investigated. With the optimum conditions,the polymer was obtained with 93. 1% yield and the number average molecular weight（ Mn）of the polymer was 2 975. 2 with PDI of 2. 64 and the polymerization residue could be recycled. Then the polymer was hydrolyzed to poly（ N-vinylformamide-co-vinylamine） with different amination degree in the hydrochloric acid solution. The hydrolysis products with the number average molecular weight of1 000 ~ 1 400 and PDI of 1. 34 ~ 1. 40 were obtained.