光引发丙烯酰胺沉淀聚合研究

以丙酮/水为溶剂，采用紫外光（UV）引发丙烯酰胺（AM）沉淀聚合，考察了聚合反应的特征以及溶剂、初始单体浓度、引发剂浓度、表面入射光强、液层厚度等参数对聚合物分子量的影响。结果表明，紫外光引发丙烯酰胺沉淀聚合过程中单体转化率和聚合物分子量都随反应时间的延长而增加，光照80min时，单体转化率可达90％以上。所得聚合物分子量为10⁵～10⁶，提高单体浓度可使聚合物分子量增加，增加引发剂浓度和提高光强导致聚合物分子量降低，液层厚度对聚合物的分子量影响不大。所得聚合物粒子粒径约为200～300nm左右，粒径分布较为均匀，溶剂组成对聚合物粒子相貌影响较大，增加水含量可使粒子粒经变大但分散性变差。

Study on photoinitiated precipitation polymerization of acrylamide

Photoinitiated precipitation polymerization of acrylamide(AM) has been carried out in a mixed solvent of water and acetone.Influences of various parameters,such as water content in the mixedsolrent,monomer concentration,initiator concentration,incident light intensity and layer thickness on the molecular weight of polymer were investigated.Both the monomer conversion and the molecular weight of polymer increased with prolonged reaction time.Generally,polymer with molecular weight of 105-106 could be obtained by the precipitation polymerization.According to the observation of SEM,the polymer particles possess a uniform size of 200-300 nm,and the particle size depended greatly on the water content in mixed solvent.