Morphology studies of treated and untreated Silicon carbide filled Polypropylene composites

Abstract

Silicon carbide filled Polypropylene (PP) composites are fabricated, where the compounding is carried out by using Z-blade mixer with filler loadings of Owt%, 10wt%, 20wt% and 30wt%. In order to improve compatibility between polypropylene matrix and silicon carbide particles, the particles surface was treated with titanate coupling agent (Lica-12). Composite sheets produced from hot press molding process are prepared for testing samples. The effect of filler loadings and incorporation of coupling agent on morphology of SiC filled PP composites are studied. The samples were sputter-coated with a fine layer of vanadium using a sputter coater and analyzed using JEOL JSM-6460LA scanning electron microscope. Comparison between morphology of treated and untreated PP-SiC composite is done. From morphology study, it can be seen that the filler distribution and SiC particle contact is improved by increasing the filler loading. Good filler distribution in the matrix improves the contact between filler and filler thus minimized the existing pores. As a result properties such as tensile strength and tensile modulus can be improved. The morphology also showed more pores exist in the 70%PP-30%SiC compared to 90%PP-lOVoSiC sample. From the result, a decrease of porosity can be observed for the composite treated with Lica-12 at 10% filler loading. However this treated SiC filled PP composites showed an increase in porosity as filler loading increased. To support the statement, SEM micrograph of 90%PP-10%SiC treated with 5%Lica-12 showed better dispersion of filler and improved wet-out between PP (matrix) and SiC (filler) compared to untreated 90%PP-10%SiC composites.