The experimental results and simulation of temperature dependence of brittle‐ductile transition in PVC/CPE blends and PVC/CPE/nano‐CaCO₃ composites

Abstract

Abstract The effect of chlorinated polyethylene (CPE) content and test temperature on the notched Izod impact strength and brittle‐ductile transition behaviors for polyvinylchloride (PVC)/CPE blends and PVC/CPE/nano‐CaCO 3 ternary composites is studied. The CPE content and the test temperature regions are from 0–50 phr and 243–363 K, respectively. It is found that the optimum nano‐CaCO 3 content is 15 phr for PVC/CPE/nano‐CaCO 3 ternary composites. For both PVC/CPE blends and PVC/CPE/nano‐CaCO 3 ternary composites, the impact strength is improved remarkably when the CPE content or test temperature is higher than the critical value, that is, brittle‐ductile transition content ( C BD ) or brittle‐ductile transition temperature ( T BD ). The T BD is closely related to the CPE content, the higher the CPE content, the lower the T BD . The temperature dependence of impact strength for PVC/CPE blends and PVC/CPE/nano‐CaCO 3 ternary composites can be well simulated with a logistic fitting model, and the simulation results can be illustrated with the percolation model proposed by Wu and Jiang. DMA results reveal that both PVC and CPE can affect the T BD of PVC/CPE blends and PVC/CPE/nano‐CaCO 3 composites. When the CPE content is enough (20 phr), the CPE is more important than PVC for determining the T BD of PVC/CPE blends and PVC/CPE/nano‐CaCO 3 composites. Scanning electron microscopy (SEM) observations reveal that the impact fractured mechanism can change from brittle to ductile with increasing test temperature for these PVC systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012