| Abstract: | Graft copolymerization of methyl methacrylate (MMA) onto nonmulberry silk fiber Antheraea assama was investigated in aqueous medium using the KMnO4–oxalic acid redox system. Grafting (%) was determined as a function of the reaction time, temperature, and monomer and initiator concentrations. The rate of grafting increased progressively with increase of the reaction time up to 4 h and then decreased. The extent of grafting was maximum at 55°C. The extent was also dependent upon monomer and initiator concentrations up to 75.5 × 10?2 and 6 × 10?3 M, respectively. The grafted products were evaluated by infrared spectroscopy and their thermal decompositions were studied by TG and DTG techniques in static air at 20°C min?1 and 30°C min?1 in the range 30–800°C. The kinetic parameters for ungrafted and grafted fibers were evaluated using the Coats and Redfern method. The grafted products were found to be thermally more stable than were those of the ungrafted fibers. The surface characteristics of the ungrafted and grafted fibers were evaluated by scanning electron microscopy. The water‐retention values (WRVs) of the grafted fibers were in decreasing order with increase in the grafting (%). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2633–2641, 2001 |
