Preparation of Canna edulis Ker Starch-Acrylic Acid Graft Copolymer by Inverse Microemulsion Method

Canna edulis Ker starch-acrylic acid graft copolymer was prepared by an inverse microemulsion method using ammonium persulfate as the initiator and N,N'-meyhylene-bisacrylamide as cross-linking agent under nitrogen protection.An inverse emulsion system containing Canna edulis Ker starch was formed under an oil-to-water ratio of 1.2:1,complex emulsifier amount of 30%,and emulsifier HLB(hydrophilic-lipophilic balance) of 7.36.The optimal copolymerization conditions of Canna edulis Ker starch and acrylic acid were acrylic acid amount of 16 mL,initiator amount of 3.5%,cross-linking agent amount of 0.8%,and neutralization degree of acrylic acid of 70%.The water-absorbing capacity of graft copolymers prepared under the optimal conditions was 1340 g/g.Meanwhile,infrared spectral analysis revealed that acrylic acid was successfully grafted onto Canna edulis Ker starch.