Synthesis and Characterization of Poly(Acrylic Acid) and Poly(Glycidyl Methacrylate) Chitosan Graft Copolymers and Their Application to Cotton Fabric

Abstract

: Graft polymerization of acrylic acid (AA) and glycidyl methacrylate (GMA) onto chitosan was independently effected in a homogeneous aqueous phase under different conditions by using potassium bromate/thiourea as a combined redox system. The grafting reaction was monitored for carboxyl and epoxy groups in the case of AA and GMA, respectively. Also monitored were percentages of graft yield (GY%), homopolymer (HP%), and total conversion (TC%). It was found that the extent of the grafting reaction, as measured by such analyses, are dependent upon monomer concentration, initiator concentration, reaction time, temperature, and material-to-liquor ratio. Based on the results obtained, the most appropriate conditions for graft copolymerization of AA onto chitosan were 4/4 mmole/L thiourea/potassium bromate and AA 30% based on weight of chitosan at 40°C for 1 hour. On the other hand, graft copolymerization of GMA occurs effectively when 6/6 mmole/L thiourea/potassium bromate and GMA 50% were used at 60°C for 1 hour. With both AA and GMA monomers, a material-to-liquor ratio of 1:25 was adequate. Chitosan-g-poly (AA) and chitosan-g-poly (GMA) were applied to cotton fabric to enhance the easy care properties. Crease recovery angle increased from 115° to 160° in the dry state and from 113° to 230° in the wet state; meanwhile, tensile strength increased from 54 Kg to 66 Kg. Dyeability, expressed as K/S, of cotton fabric treated with these copolymers also increased.