Modification of Natural Polymers: Graft Copolymerization of Methyl Methacrylate onto Rayon Fiber Initiated by Ceric lons - A Study in Methacrylate onto Rayon Fiber Initiated by Ceric lons - A Study in Swelling and Thermal Properties

摘要

Modification of rayon fiber for more diversified end-uses has been attempted by grafting methyl methacrylate (MMA) initiated by Ce~(+4) ions. Optimum grafting conditions such as concentration of monomer, initiator and nitric acid, amound of water, reaction time and temperature have been evaluated. The graft copolymers and the ungrafted rayon fiber have been characterized by thermogravimetric analuysis and by swelling studies in DMF, water and 1-butanol. The trend in the swelling behavior of the grafted sample follows DMF > water > 1-butanol order which is different from that observed for ungrafted sample, namely, water > DMF > 1-butanol. The grafted sample shows improved thermal stability in contrast to ungrafted fiber as observed from higher initial decomposition temperature (IDT) and higher energy of activation (E_(act)) in the overall degradation process. However, the overall mechanism of degradation follows the same model