Morphology and mechanical characteristics of compatibilized polyamide 6-liquid crystalline polymer composites

The blend behaviour of polyamide 6 (PA6) and thermotropic liquid crystalline polymer (LCP) compatibilized with maleic anhydride grafted polypropylene (MAP) was studied by means of scanning electron microscopy (SEM), drop weight Charpy impact test, static tensile and dynamic mechanical measurements. The blending was performed via direct injection moulding of PA6(MAP) with LCP pellets at 285 degrees C. Tensile measurements indicated that the tensile strength and modulus increase with increasing LCP content and the mechanical properties are above predictions of the rule of mixtures. This was correlated with the formation of LCP fibrils with large aspect ratios in both skin and core sections of the PA6(MAP)/LCP blends. Charpy impact test showed that the impact fracture toughness decreases significantly with the addition of small amounts of LCP content. However, the impact toughness appeared to increase as the LCP content is above 30 wt%. This was attributed to the enhanced fibrillation of the LCP dispersed phase at higher concentration. (C) 1997 Elsevier Science Ltd.