淀粉丙烯酰胺反相乳液体系的稳定性及接枝共聚反应

Study on the Stability of Starch/Acrylamide Inverse Emulsion and the Graft Copolymerization

以Span80和Tween80为复合乳化剂,制备了稳定的W/O型淀粉丙烯酰胺反相乳液。探讨了乳化剂HLB值、油水比、乳化剂用量对乳液类型及稳定性的影响,得到最佳配方:乳化剂HLB值6.49、油水比1∶1、乳化剂用量3%。在此反相乳液体系中,成功进行了淀粉丙烯酰胺接枝共聚反应,通过正交实验得到最佳工艺条件为反应温度50℃、反应时间2 h、引发剂浓度0.0175 mol/L、单体与淀粉质量比1.5。在此实验条件下合成的淀粉丙烯酰胺接枝共聚物之聚合率和接枝效率分别可达95.46%和95.10%以上。

The water-oil inverse emulsion was prepared in present of cassava starch and acrylamide with the compounds of span80 and tween80 as emulsifier. The effect factors on the types and stability of the inverse emulsion were discussed, and the optimum conditions for forming stable water-oil inverse emulsion were attained as the HLB value of mixed emulsifier at 6. 49, the mass ratio of oil to water in 1 ： 1, and the content of the mixed emulsifier at 3%. The graft copolymerization of acrylamide onto cassava starch was conducted successfully in above inverse emulsion. By orthogonal experiment the optimum conditions were determined as temperature at 50℃, time in 2 h, the concentration of initiator in 0. 0175 mol/L, and mass ratio of acrylamide to starch in 3 ： 2. The rate of polymerization and the graft efficiency were 95.46 % and 95.10 %respectively.