丙烯酸酯反相微乳液聚合动力学

KINETICS OF ACRYLATES COPOLYMERIZATION IN INVERSE MICROEMULSION

对以甲基丙烯酸甲酯 /丙烯酸丁酯混合单体为连续油相、十二烷基硫酸钠为乳化剂、丙烯酸为反应性助乳化剂构建的反相微乳液体系 ,以偶氮二异丁腈引发微乳液聚合 ,系统考察了引发剂浓度、乳化剂浓度、助乳化剂浓度、水相质量分数及反应温度对表观聚合速率的影响 .讨论结果表明 ,微乳液聚合中液滴成核相当重要 ,聚合速率随体系中引发剂浓度、丙烯酸浓度、水相质量分数及聚合温度的升高而加快 ,随体系中乳化剂浓度的增大而降低 ,并得出动力学关系式 ,且聚合反应表观活化能为 114kJ·mol-1.

The kinetics of acrylates copolymerization initiated with azobisisobutyronitrile (AIBN) in inverse microemulsions composed of methyl methacrylate (MMA) -butyl acrylate (BA)/dodecyl sodium sulfate (SDS) -acrylic acid (AA)/water was studied. The results showed that the apparent polymerization rate at 5% conversion increased with increased AIBN concentration, AA concentration, aqueous fraction and reaction temperature while decreased with increased SDS concentration, and the kinetic relation was obtained. Nucleation in aqueous droplet was considered to be important. Furthermore, the total apparent activation energy was found to be 114 kJ&middotmol-1.