Sailes Mukhopadhyay

Characterization of graft copolymeres of methyl cellulose and polyacrylamide by thermogravimetry

Thermal stability and degradation kinetics of methyl cellulose, polyacrylamide and methyl cellulose grafted with different amounts of polyacrylamide were investigated by thermogravimetry. Polyacrylamide was found to be more stable than methyl cellulose. The thermal stabilities of the graft copolymeres lie in between these two extremes. The order of reaction, n, and energy of activation, E, of the thermal degradation were determined for all polymer samples. It was found that E for the degradation of polyacrylamide (41,4 kcal/mol = 173,2 kJ/mol) is higher than that of methyl cellulose (31,3 kcal/mol = 131,0 kJ/mol) and that E for the graft copolymers lies in between those of the two homopolymers. The over-all reaction order of the degradation reactions was found to be unity for all polymer samples investigated.