Thermal stabilities of poly(vinyl chloride)/calcium carbonate (PVC/CaCO3) composites

Poly(vinyl chloride)/calcium carbonate (PVC/CaCO3) composites with micrometer or nanometer CaCO3 as fillers were prepared by the solution blending method. The thermogravimetric analysis (TGA) of the composite films conducted in N-2 atmosphere showed that the addition of the CaCO3 fillers could improve their thermal stabilities. It was also found that the nanometer CaCO3 filler provided better thermal stabilities than the micrometer fillers even with a smaller amount. The mechanism of the improvements was investigated by a facile chemical analysis developed to examine the thermal stabilizing effect of calcium carbonate particles with different sizes in PVC/CaCO3 composites after the pyrolysis of the samples in an air atmosphere in an oven.