THE EFFECT OF COMPATIBILIZATION ON BLENDS OF POLYPROPYLENE WITH A LIQUID-CRYSTALLINE POLYMER

Compatibilization of blends of polypropylene (PP) with a thermotropic liquid-crystalline polymer (LCP) was considered in an attempt to improve the mechanical properties obtained by blending alone. The effect of compatibilization was investigated on injection-moulded plaques and tensile bars. Significant improvements were seen in the values of tensile modulus and strength. Substantial improvements were also obtained for torsion modulus and compliance. The surface finish of the blends was very smooth and homogeneous. The morphological investigations showed that the key to property enhancements lay in improved interfacial adhesion and a less phase-separated and more uniform dispersed-phase (LCP) distribution. The properties of the compatibilized PP/Vectra B blends compared favourably with those of the glass-filled PP.