MORPHOLOGY AND PERFORMANCE OF POTASSIUM TITANATE WHISKER-REINFORCED POLYPROPYLENE COMPOSITES

Titanate whisker-reinforced polypropylene composites were prepared in a twin-screw extruder followed by injection molding. The whiskers were surface treated with tetrabutyl orthotitanate prior to blending. The static and dynamic mechanical properties, impact strength, and thermal properties of the composites were investigated. Static tensile measur ements showed that the tensile strength and Young's modulus of the com posites increased with increasing whisker content. However, the Izod i mpact tests indicated that the impact strength of longitudinal samples remained unchanged with the addition of whisker up to 10 wt %. Therea fter, it shows a continuous decrease with increasing whisker content. The thermogravimetric and dynamic mechanical tests demonstrated that t he heat-resistance and thermooxidative stability for the composites al so increased with increasing whisker content. Scanning electron micros copic observations revealed that the whiskers within the composites we re oriented uniformly. The experimental data were compared with the we ll established mechanical models to evaluate the reinforcing efficienc y. (C) 1998 John Wiley & Sons, Inc.