反相悬浮聚合法合成超高分子量聚丙烯酸钠

Synthesis of super high molecular weight sodium polyacrylate by inverse suspension polymerization

以丙烯酸钠和丙烯酰胺为单体 ,采用反相悬浮聚合法制备了超高分子量的聚丙烯酸钠 (NaPA)。研究了引发剂浓度、抗交联剂及其他助剂对合成产物聚丙烯酸钠性能的影响。结果表明 ,(NH4 ) 2 S2 O8的最佳用量是 0 15 %(质量分数 ) ;随着CO(NH2 ) 2 用量的增加分子量提高明显 ;在聚合体系中加入甲基丙烯酸N ,N -二甲氨基乙酯(DMAEMA)可提高分子量但用量应控制在 9 4× 10 -4 %～ 15 6× 10 -4 %之间。同时用抗交联剂防止交联反应 ,结合使用醋酸钠和异丙醇这两种分子量调节剂不仅能提高分子量而且溶解性也得到改善。最终得到了分子量高达3 0× 10 7的产物 。

Synthesis of super high molecular weight sodium polyacrylate by inverse suspension polymerization of acrylamide and sodium acrylate was studied. The effects of the three initiators concentrations, two kinds of regulators of molecular weight and the agents for preventing cross linking on the molecular weight and dissolubility of sodium polyacrylate were studied. It is found that the best concentration of (NH 4) 2S 2O 8 is 0 15% (mass ratio), with the increase in CO(NH 2) 2 concentration the molecular weight significantly increased, and by adding DMAEMA the molecular weight is also increased, but its concentration scope is 9 4×10 -4 %～15 6×10 -4 %. In addition, the agents for preventing cross linking were used to prevent the cross linking reaction. It is also found that adding sodium acetate and iso propyl alcohol (two kinds of regulators of molecular weight ) not only increase the molecular weight but also improve the dissolubility. Super high molecular weight (3 00×10 7) is obtained. In contrast with the previous study, the molecular weight and dissolubility are greatly improved.