Effect of filler addition and weathering conditions on the performance of PVC/CaCO3 composites

Abstract

This study deals with the effects of calcium carbonate (CaCO3) fillers and hygrothermal aging on the performance of polyvinylchloride (PVC). The properties of the PVC/CaCO3 composite were studied before and after aging in water up to 3 months at 24°C ± 3°C, 70°C, and 90°C. In terms of fillers effect, it was found that the incorporation of fillers in PVC induces an increase in both Tg value and storage modulus; however, it had no significant effect on the water absorption. However, the addition of fillers has resulted in an improvement in the elastic modulus, whereas it has shown harmful effect on the tensile strength and elongation at break. Concerning flexural properties, an important filler percentage, that is, 35 wt%, is proved to be the optimum content to achieve maximum strength and modulus as well as wear properties. In terms of aging impact, it was found that shift in color on aging occurs noticeably. Elastic modulus, tensile strength, flexural strength, and flexural modulus increase with increasing temperature from ambient to 70°C, whereas they decrease at 90°C. Dynamic mechanical thermal analysis confirmed that at high temperature, the absorbed water affects the PVC matrix during aging. As a result, a loss in strength and stiffness but a gain of ductility was observed. The great quantity of absorbed water acts as a barrier layer and, thus, minimizes the wear. POLYM. COMPOS., 37:2171–2183, 2016. © 2015 Society of Plastics Engineers