In situ compatibilization of a polyetherimide and a thermotropic polyester using an epoxy resin

This study examines the compatibilization of the polyetherimide Ultem 1000 with the thermotropic liquid crystalline polymer Vectra A 950 by using an epoxy resin (PKFE) as compatibilizer. IR spectroscopy and electron-microscopic morphological analysis indicate the grafting of PKFE molecules on fibrillar domains of Vectra during melt mixing. Moreover, morphological analysis shows that the addition of PKFE improves the dispersion and decreases the size of Vectra fibrils. Both Vectra and PKFE significantly reduce the glass transition temperature of Ultem in ternary blends. The tensile modulus and the ultimate strength of the blends are improved with respect to those of neat Ultem. However, the final materials are very fragile. The roles of Vectra and PKFE are discussed.