Photograft copolymerization of methyl methacrylate on silk fiber using titanium(III) chloride-potassium persulphate redox initiator in a limited aqueous system. I

Graft copolymerization of methyl methacrylate (MMA) onto mulberry silk fibe rs has been investigated in a limited aqueous system employing titanium(III ) chloride-K2S2O8 as the redox initiator under a photoactive condition with visible light. Polymerization in the presence of light at 32 +/- 1 degrees C has been found to be more pronounced than in the dark under identical co nditions. The percentage of grafting, the percentage of total conversion, a nd the percentage of grafting efficiency have been studied by varying the r eaction time, concentration of monomer, initiator concentration, solvent co mposition, and pH of the medium. A high percentage of grafting (similar to 93%), high grafting efficiency (similar to 97%), and the percentage of tota l conversion (similar to 25%) have been obtained with little homopolymer fo rmation. Characterization of the grafted fibers has been investigated by Fo urier transform infrared spectroscopy and scanning electron microscopy. Fin ally, the reaction mechanism has been discussed by considering hydrogen bon ding. (C) 1999 John Wiley & Sons, Inc.