Study on the miscibility and phase behavior of polyoxymethylene with Novolak

The miscibility and phase behavior of the blends of polyoxymethylene (POM)/ Novolak were investigated by the cloud point method, which showed that the POM/Novolak blends exhibited a lower critical solution temperature. The mel ting point of POM decreased when diluted with Novolak. From the melting tem perature depression of POM, a negative interaction parameter (chi) between POM and Novolak was obtained. The IR spectrum revealed that the miscibility between POM and Novolak was caused by the specific interaction between the OH groups of Novolak and the ether oxygen atoms of POM. The morphology of the blends investigated by polarized light microscopy showed that the size of spherulites of POM was sharply decreased by its mixing with Novolak. Thi s suggests that Novolak be used as a compatibilizer for POM.