丙烯酸钠反相乳液聚合

以阴离子乳化剂制备丙烯酸钠反相乳液，用γ射线引发其聚合，用扫描电镜观测了聚合前后粒径的变化；并在聚合过程中改变剂量率观测了聚合速率的变化．这两个实验结果都显示聚合以液滴成核为主，即聚合机理类似于悬浮聚合．与以司盘８０为乳化剂的丙烯酸钠反相乳液聚合相比，体系与司盘体系的聚合动力学基本相似；但是体系中的分散液滴比司盘体系要大，结果使得在动力学上体系更类似于悬浮聚合的动力学．从聚合机理看，反相乳液聚合实际上就是粒子分散得比较小的反相悬浮聚合．

INVERSE SUSPENSION POLYMERIZATION OF SODIUM ACRYLATE

The inverse emulsion of sodium acrylate was stabilized with an anionic emulsifier (sodium 12 butinoyloxy 9 octadecenate). The polymerization was initiated with γ ray.The particle sizes of the inverse emulsion before and after polymerization were observed with scanning electron microscope.The effect of changing dose rate during polymerization on polymerization rate was also determined to understand the nucleation mechanism.These observed results hinted that the polymerization nucleates in monomer droplet.As in the inverse emulsion stabilized with Span 80,the expression of polymerization kinetics was similar to that in suspension polymerization.At most cases,the molecular weights of polymer were smaller than that produced in systems stabilized with Span80.