Poly(phenylene sulphide)/thermotropic liquid crystalline polymer blends: A comparative study of thermal properties, phase behaviour and morphology of blends generated by different techniques

Abstract

Blends of poly(phenylene sulphide) and poly(ethylene terephthalate-co-oxybenzoate), an aliphatic—aromatic thermotropic liquid crystalline polymer (TLCP), were prepared by different blending techniques and their thermal properties, phase behaviour and morphology were compared using differential scanning calorimetry (d.s.c.), polarized light optical microscopy (p.l.o.m.) and scanning electron microscopy (s.e.m.). Melting transitions and phase behaviour of the blends were dependent on the preparation method. While blends prepared by the precipitation method appeared monophasic, those prepared by melt-mixing were seen to be phase separated. The melt-mixed blends show macrophase-separated morphology indicating poor phase mixing whereas the co-precipitated blends of the same composition exhibit a disperse-type morphology, as observed by p.l.o.m. In comparison to melt-mixed blends, co-precipitated blends were seen to be uniform and continuous.