Graft copolymerization of methylmethacrylate onto non-mulberry silk-Antheraea assama using potassium permanganate-oxalic acid redox system

The graft copolymerization of methyl methacrylate (MMA) onto non-mulberry s ilk fibre Antheraea assama using potassium permanganate (KMnO4)-oxalic acid redox system was carried out. Effects on grafting of various parameters, c oncentration of monomer and initiator, reaction time and temperature were s tudied. The graft yields increased significantly with increase of the monom er concentration and with increasing concentration of initiator, Mn(IV), up to 6 x 10(-3) M, but decreased thereafter. The rate of grafting increased progressively with the increase of reaction time up to 4 h and then decreas ed. The extent was also dependent upon reaction temperature, and at 50 degr ees C, the graft yield was maximum. The characteristics of the grafted prod ucts were evaluated by infrared spectroscopy, while the thermal decompositi ons of the grafted fibres were studied using thermogravimetric (TGA) and di fferential thermogravimetric (DTG) techniques at heating rates 20 degrees C and 30 degrees C min(-1) in static air in the temperature range 30-800 deg rees C. The grafted fibres were thermally more stable and more hydrophobic in nature than the ungrafted fibres. (C) 2000 Elsevier Science Ltd. All rig hts reserved.