光引发玉米淀粉-丙烯酸反相乳液接枝共聚合制备高吸水性树脂

采用2,2-二甲氧基苯基苯乙酮、二苯甲酮及2,4,6-三甲基苯甲酰基-二苯基氧化膦等多种光引发剂,引发玉米淀粉-丙烯酸/水/煤油/失水山梨醇单油酸酯+壬基酚聚氧乙烯醚反相乳液接枝共聚合,探讨了光引发剂的种类和浓度、玉米淀粉和乳化剂的用量及光照时间对反相乳液接枝共聚合的影响。实验结果表明,多种光引发剂都可引发玉米淀粉-丙烯酸反相乳液接枝共聚合,30m in内单体转化率达到65.31%~92.61%。将玉米淀粉-丙烯酸反相乳液接枝共聚物适度交联,可制得颗粒状高吸水性树脂,交联剂的含量和加入方式都影响树脂的吸水性能。二次聚合可提高树脂的吸水倍率和耐盐性能;扫描电镜观察显示,二次聚合结束时乳胶粒子的粒径增大。

Photo- Initiated Inverse Emulsion Graft Copolymerization of Acrylic Acid onto Corn Starch to Prepare Super Water- Absorbent Resin

Graft copolymerization of acrylic acid(AA)onto corn starch(ST)initiated by different photo-initiators was carried out in inverse emulsion system using kerosene as reaction medium,and sorbitan monooleate blended with nonylphenol polyoxyethylene ether as emulsifier.Effects of reaction conditions,namely types and mass fraction of photo-initiator,mass fraction of corn starch and emulsifier,and reaction time,on graft copolymerization were investigated.Several photo-initiators could be applied and monomer conversion could reach 65.31%—92.61% within 30min.The super water-absorbent resin in particle form was prepared by proper cross-linking of the graft copolymer.Water absorption capacity of resin depended on mass fraction of cross-linking agent and its addition manners.Properties and particle size of resin could be improved by second inverse emulsion graft copolymerization.