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.