Processing behavior of polycarbonate/functionalized-ethylene copolymer blends

The melt blending of polycarbonate (PC) and ethylene-methacrylic acid copol ymers (EFC) either in the acid form (EFC-H) or partially neutralized with s odium (EFC-Na) or zinc (EFC-Zn) was investigated. Torque monitoring of the blending showed that the polymers are capable of reacting generating new ch emical species that increase the melt viscosity. As general behavior, the t orque curves pass by a maximum that takes place before 30 min, the final to rque being higher than that of the individual polymers. SEC analyses reveal that PC degradation also occurs and is stronger in the case of blends with EFC-Na that acts to catalyze PC degradation, promoting CO, formation. FTIR studies on chloroform insoluble fractions of the PC/EFC-Zn blends showed t hat in addition to a very small number of carbonate groups, feature absorpt ion bands of aromatic ester and hydroxyl groups appear in the new chemical species formed during the reactive processing.