CLOUD-POINT CURVES AND INTERACTION PARAMETERS OF UNSATURATED POLYESTER STYRENE SOLUTIONS

Experimental cloud-point curves of unsaturated polyester (UP) prepolymers with styrene have been determined in this work. The UP prepolymers are copolymers based on maleic anhydride and two types of glycols: diethylene glycol (DEG) and neopentyl glycol (NPG). For UP prepolymers with the same number-average molecular weight (M(n)BAR) and the same hydroxyl functionality (f(OH)BAR), the miscibility with styrene increases when the NPG content increases. For the different chemical structures, the calculated solubility (delta) and interaction (chi) parameters of the prepolymers decrease when the NPG content increases. A linear correlation between the theoretical critical temperatures (T(c)) and the interaction parameters (chi) is observed.