Nanocomposites of poly(vinyl chloride) and nanometric calcium carbonate particles: Effects of chlorinated polyethylene on mechanical properties, morphology, and rheology

Nanocomposites of poly(vinyl chloride) (PVC) and nano-calcium carbonate (CaCO3) particles were prepared via melt blending, and chlorinated polyethylene (CPE) as an interfacial modifier was also introduced into the nanocomposites through preparing CPE/nano-CaCO3 master batch. The mechanical properties, morphology, and rheology were studied. A moderate toughening effect was observed for PVC/nano-CaCO3 binary nanocomposites. The elongation at break and Young's modulus also increased with increasing the nano-CaCO3 concentration. Transmission electron microscopy (TEM) study demonstrated that the nano-CaCO3 particles were dispersed in a PVC matrix uniformly, and a few nanoparticles agglomeration was found. The toughening effect of the nano-CaCO3 particles on PVC could be attributed to the cavitation of the matrix, which consumed tremendous fracture energy. The notched Izod impact strength achieved a significant improvement by incorporating CPE into the nanocomposites, and obtained the high value of 745 J/m. Morphology investigation indicated that the nano-CaCO3 particles in the PVC matrix was encapsulated with a CPE layer through preparing the CPE/nano-CaCO3 master batch. The evaluation of rheological properties revealed that the introduction of nano-CaCO3 particles into PVC resulted in a remarkable increase in the melt viscosity. However, the viscosity decreased with addition of CPE, especially at high shear rates; thus, the processability of the ternary nanocomposites was improved. (C) 2004 Wiley Periodicals, Inc.