以机械活化淀粉为基材,丙烯酰胺(AM)、丙烯酸(AA)为单体,采用反相乳液法合成了接枝共聚物;考察了各因素对接枝共聚反应的影响。实验结果表明,在实验考察范围内的适宜反应条件为引发剂浓度7.30mmo/L、丙烯酸中和度80%、m(AM):m(AA)=0.67、V(油):V(水)=1.2:1、反应温度50℃、7Ft(单体):m(淀粉)=1.6:1;在该反应条件下单体转化率为95.30%,接枝率为61.87%、接枝效率为78.49%。对比原淀粉在类似的条件下,单体转化率为90.70%,接枝率和接枝效率分别为55.70%和68.36%。机械活化显著地艘高了玉米淀粉在反相乳液中的接枝共聚反应活性。
A graft copolymer was synthesized by graft copolymerization of starch pretreated with mechanical activation with acrylamide (AM) and acrylic acid (AA) in inverse emulsion. The several effects were investigated on the reaction of graft co-polymerization. The results show that the optimal conditions of reaction are the concentration of initiator 7.30 retool/L, neutralization degree of AA 80 %, the mass ratio of AM to AA 0.67, volume ratio of oil to water 1.2 : 1, reaction temperature 50 ℃ and the mass ratio of starch to monomer 1.6 : 1, while the monomer conversion, grafting percentage and grafting efficiency are 95.30 %, 61.87 % and 78.49 %, respectively. Compared with the raw maize starch, under the similar conditions, the monomer conversion, grafting percentage and grafting efficiency are 90.70 %, 55.7 % and 68.36 % respectively. It can be concluded that the chemical reaction activity of maize starch is significantly enhanced by mechanical activity during the graft eopolymerization process in inverse emulsion.