反相悬浮法合成高分子量聚丙烯酸钠

Inverse Suspension Polymerization of Polyacrylate Sodium

探讨了体系乳化剂、中和度对聚合稳定性的影响 ,研究引发体系、链转移剂、交联剂等与分子量、凝胶含量的关系。结果表明 ,当选用 Span- 6 0作为乳化剂、单体中和度为 93%时体系稳定性较好。用一定配比的过硫酸铵氧化还原体系为引发剂 ,以异丙醇作链转移剂 ,在适量的交联剂 N ,N'-亚甲基双丙烯酰胺和盐类的存在下 ,聚合得到了粒径为 5 0～ 2 0 0μm、分子量高达 10 0 0× 10 4 左右的聚丙烯酸钠透明粒子 ,并且解决水溶液聚合后期体系粘度大、搅拌和传热困难等问题。

Polyacrylate sodium (PAS) of high molecular weight synthesized by inverse suspension polymerization was studied in this paper. The effects of emulsifier and neutralization degree on the stability of polymerization were investigated. Results showed that the stability for the system was good in the presence of emulsifier of Span-60 and with 93% neutralization degree of acrylic acid. Furthermore, the transparent particles of PAS with the molecular weight of 10 million and the diameter of from 50 to 200 micron were gained with ammonium persulphate of appropriate proportion redox as initiator, isopropyl alcohol as chain transfer agent and in the presence of N,N'-dimethyl bisacrylamide and sodium chloride. Meanwhile, some problems such as agitation and heat transfer during the later stage under the conditions with the high viscosity could be solved by inverse suspension polymerization instead of aqueous solution polymerization.