CORRELATION OF THERMAL-ANALYSIS DATA AND HYDROLYSIS RESISTANCE OF POLYCARBONATES

The initial activation energy at zero conversion E(o) of thermooxidati ve decomposition has been taken as a measure of thermal stability of p olycarbonates (PC) and E(0) has been correlated with the relative hydr olysis rate rh as a measure of their hydrolyse resistance. It is sugge sted that both decomposition processes are initiated by the same mecha nism, the attack of hydrolytic agent onto ester C-O bonds. The followi ng values of E(o) have been found: 187 (PC-M) > 87 (PC-A) > 43 (PC-C) kJ/mol, and they are correlated with values of r(h) being 0.01 (PC-M) < 1 (PC-A) < 4.4 (PC-C). It has been found, using a computer modeling technique, that both E, and rh depend on the minimized energy of confo rmations.