In situ hybrid composites of thermoplastic poly(ether ether ketone), poly(ether sulfone) and polycarbonate

In order to overcome the poor processability of short-fibre-reinforced thermoplastics and to enhance the mechanical performance of thermoplastics reinforced with thermotropic liquid crystalline polymer (TLCP) fibrils (in situ composites), a new concept of an in situ hybrid composite has been put forward. This group of polymer-matrix composites, basically consisting of a thermoplastic matrix, inorganic fibres of micrometeres in diameter and organic TLCP fibrils of submicrometres in diameter, has hybrid effects of rheology, geometry and mechanics originating from these two reinforcements at two orders of magnitude. In situ hybrid composites, such as TLCP/carbon-fibre-reinforced poly(ether ether ketone), TLCP/carbon-fibre-reinforced poly(ether sulfone) and TLCP/glass-fibre-reinforced polycarbonate systems, show lower melt viscosity and excellent processability, minimized breakage of fibres added, favoured orientation of reinforcing fibres and enhanced tensile strength and modulus, flexural strength and modulus and impact strength, compared to their pristine short-fibre-reinforced composites. (C) 2000 Elsevier Science Ltd. All rights reserved.