EFFECT OF CALCIUM SULPHATE NANOPARTICLES ON FUSION, MECHANICAL AND THERMAL BEHAVIOUR POLYVINYL CHLORIDE (PVC)

Abstract

Calcium Sulphate [ CaSO 4] was synthesized by in-situ deposition technique and its nano size (60 to 100 nm) was confirmed by Transmission Electron Microscopy (TEM). Composites of the filler CaSO 4 (micro and nano) and the matrix poly (vinyl chloride) ( PVC ) were prepared with different filler loading (0-5 wt. %) by melt mixing. The Brabender torque rheometer equipped with an internal mixer was used for preparation and evaluation of fusion behaviour of composites of different formulations. The effect of nano and micro- CaSO 4 content on the structure and properties of composites was studied. The nanostructures and dispersion were studied by wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The mechanical and thermal properties of PVC / micro and nano- CaSO 4 composites were characterized using Universal Testing Machine (UTM) and Thermo Gravimetric Analyzer (TGA). From the results of WAXD and SEM the flocculation of CaSO 4 nanoparticles were observed on the surfaces of PVC matrix. The thermal analysis results showed that the first thermal degradation onset (T onset) of PVC /nano- CaSO 4 composites for 1 wt. % of filler were higher as compared with corresponding microcomposites and pristine PVC . However, the tensile strength was decreasing with increasing filler content while, it shows increment in magnitude at 1 and 2 wt. % of nano- CaSO 4 as compared with corresponding micro- CaSO 4 as well as pristine PVC .