REACTIVE BLENDING OF POLYPIVALOLACTONE WITH POLYCARBONATE

Blends of polypivalolactone (PPVL) with bisphenol-A polycarbonate (PC) were studied. Physical PPVL/PC blends showed one T(g) close to the T( g) of 145-degrees-C for PC, indicating immiscibility. Reactive blendin g of PPVL and PC with 0.5 wt.-% tetrabutylorthotitanate was performed in diphenyl ether (260-degrees-C) and in a twin screw extruder (TSE) a t 280-degrees-C. Based on the results from NMR, FT-IR and thermal anal ysis, it was concluded that interchange reactions had occurred. The th ermal properties indicated that, due to these interchange reactions, P PVL/PC blends had become more miscible. Although blending in a TSE was more efficient with respect to interchange reactions compared with bl ending in diphenyl ether, complete randomization was not observed.