Effects of microscale calcium carbonate and nanoscale calcium carbonate on the fusion, thermal, and mechanical characterizations of rigid poly(vinyl chloride)/calcium carbonate composites

Abstract

Abstract A Haake torque rheometer equipped with an internal mixer has been used to study the influence of microscale calcium carbonate (micro‐CaCO 3 ) and nanoscale calcium carbonate (nano‐CaCO 3 ) on the fusion, thermal, and mechanical characteristics of rigid poly(vinyl chloride) (PVC)/micro‐CaCO 3 and PVC/nano‐CaCO 3 composites, respectively. The fusion characteristics discussed in this article include the fusion time, fusion temperature, fusion torque, and fusion percolation threshold (FPT). The fusion time, fusion temperature, and FPT of rigid PVC/calcium carbonate (CaCO 3 ) composites increase with an increase in the addition of micro‐CaCO 3 or nano‐CaCO 3 . In contrast, the fusion torque of rigid PVC/CaCO 3 composites decreases with an increase in the addition of micro‐CaCO 3 or nano‐CaCO 3 . The results of thermal analysis show that the first thermal degradation onset temperature ( T onset ) of rigid PVC/micro‐CaCO 3 is 7.5 °C lower than that of PVC. Meanwhile, the glass‐transition temperature ( T g ) of rigid PVC/micro‐CaCO 3 is similar to that of PVC. However, T onset and T g of PVC/nano‐CaCO 3 composites can be increased by up to 30 and 4.4%, respectively, via blending with 10 phr nano‐CaCO 3 . Mechanical testing results for PVC/micro‐CaCO 3 composites with the addition of 5–15 phr micro‐CaCO 3 and PVC/nano‐CaCO 3 composites with the addition of 5–20 phr nano‐CaCO 3 are better than those of PVC. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 451–460, 2006