反相乳液聚合制备丙烯酰胺-丙烯酸铵共聚物

采用反相乳液聚合法,以液体石蜡为连续相、丙烯酰胺和丙烯酸水溶液为分散相、N,N′-亚甲基双丙烯酰胺为交联剂、过硫酸铵为引发剂,制备了丙烯酰胺(AM)-丙烯酸铵(AA)共聚物;考察了引发剂含量、单体AM含量、复合乳化剂Span-80与Tween-80的配比、聚合体系pH、聚合温度、油水比等对AM-AA共聚物性能的影响。较佳的聚合条件为:过硫酸铵占单体总质量的0.7%,AM占丙烯酸质量的40%～45%,m(油)∶m(水)=1.1,m(Span-80)∶m(Tween-80)=92∶8(Span-80和Tween-80复合乳化剂的亲水亲油平衡值约为5.2),聚合温度60～70℃,聚合体系pH约为9.0。在此条件下,制得的AM-AA共聚物的黏度较大,稳定性较好。

Preparation of Acrylamide-Ammonium Acrylate Copolymer by Inverse Emulsion Polymerization

Copolymer of acrylamide and ammonium acrylate was prepared by inverse emulsion polymerization,with liquid paraffin as continuous phase,acrylic acid and acrylamide aqueous solution as dispersing phase,N,N′-methylene-bisacrylamide as cross-linking agent,Span-80 and Tween-80 as complex emulsifier,and ammonium persulfide as initiating agent. The influences of some factors on viscosity of the obtained copolymer were investigated,namely initiator dosage,mass ratio of Span-80 to Tween-80,pH of polymerization system,reaction temperature and mass ratio of oil to water. Optimal conditions are: mass fraction of ammonium persulfide in acrylamide and ammonium acrylate 0.7%,mass fraction of acrylamide in acrylic acid 40%-45%,m(Span-80) ∶m(Tween-80) 92 ∶8 (Span-80 and Tween-80 complex emulsifier with hydrophilic-lipophilic balance value about 5.2),mass ratio of oil to water 1.1,pH of polymerization system about 9.0 and temperature 60-70 ℃. The obtained copolymer is with high viscosity and stability. The copolymerization process is easily to be operated and environmental friendly. It has big potential for application in industry.