Studies on properties of Molybdenum filed Polypropylene composites

Abstract

Molybdenum filled polypropylene (PP/Mo) composites were prepared by using the Z-blade mixer at processing temperature 190°C and a speed of 35rpm with different filler loading varying between 0% and 40% by weight. A titanate coupling agent, LICA-12 was added to improve the adhesion between matrix and filler material. Effect of filler loadings and coupling agent addition on tensile properties, flexural properties and swelling behaviour of molybdenum (Mo) filled polypropylene (PP) composites were investigated. Based on the tensile test, it was found that with increasing filler loading, tensile strength and elongation at break decreased. However, PP/Mo composites with LICA-12 showed greater tensile properties compared to PP/Mo composites without LICA-12. The addition of titanate coupling agent, LICA-12 has improved the adhesion between Mo filler and PP matrix by promoting better wetting of filler by matrix. Hence, the properties of composites have been slightly increased. The result from flexural testing on PP/Mo composites showed increments in flexural strength and flexural modulus with respect to the increasing filler loading. These results revealed that the embedded Mo particles were responsible in increasing stiffness of the composites. PP/Mo composites with LICA-12 showed better flexural properties than PP/Mo composites without LICA-12. The presence of LICA-12 has promoted better adhesion and consequently increased the flexural properties. Overall, the coupled PP/Mo composites present better mechanical properties as compared to the uncoupled PP/Mo composites. LICA-12 imparts increased in functionality to fillers in plastics thus allowing fillers to act as mechanical properties improvers. In addition, the incorporation of Mo particles in PP matrix decreased the ability to absorb water in PP/Mo composite system compared to control (pure PP). The rate of water absorption decreased when there was increasing in filler loading. The presence of titanate coupling agent has improved water resistance in the PP/Mo composites, where the coupled PP/Mo composites showed lower water absorption rate compared to the uncoupled one. As a conclusion, utilization of Mo powder was found as potential filler in increasing some of mechanical properties of metal-filled polymer composites besides the ability of this metal filler in improving the water absorption resistant in polymeric system.