Mechanical and thermal properties of unsaturated polyester/calcium carbonate nanocomposites

Abstract

In this study, the nano-sized calcium carbonate (CaCO3) is synthesized using an in situ deposition technique and characterized using TEM. The particle size is found to be around 50–60 nm. Nanocomposites of UPR and nano-CaCO3 particles are prepared by casting technique. The TEM study demonstrates that nano-CaCO3 particles are dispersed in a UPR matrix uniformly and few agglomerations are found at and above 5 wt% of nano-CaCO3 in the UPR matrix. XRD studies reveal the formation of nanocomposites. The mechanical and thermal properties of UPR/CaCO3 nanocomposites are better than those of pure UPR. Up to 5 wt% loading of nano-CaCO3 in the UPR matrix, the tensile, flexural, and impact strengths slightly improved. The flexural modulus increases with increase in nano-CaCO3 concentration. The morphology of the impact fracture surface of nanocomposites is analyzed by means of SEM. The dynamic mechanical analysis of the nanocomposites clearly indicates a progressive increase in Tg with the progressive addition of nano-CaCO3 till a loading of 5 wt% of nano-CaCO3 in the unsaturated polyester resin.