Influence of the diameter of CaCO3 particles on the mechanical and rheological properties of PVC composites

PVC composites filled with CaCO3 particles with different diameter (about 40, 80, 500, 25000 nm) were prepared by using a single-screw extruder. The mechanical and rheological properties of the composites were investigated. The results showed that while the diameter of CaCO3 nanoparticles was smaller, the mechanical properties of composites were higher. By adding 40-nm CaCO3 nanoparticles into the PVC matrix, the single-notched impact strength of the nanocomposite at room temperature reached 82.4 kJ/m(2), which was 3.5 times that of the PVC matrix without CaCO3 (23.3 kJ/m(2)) and 4.6 times that of the PVC blend filled with micro-CaCO3 (17.9 kJ/m(2)). The tensile and flexural properties of nanocomposites were also prior to those of the composites with 500-nm and 25-mu m CaCO3 particles. The CaCO3 particles could make the rheological property of PVC composites worse. Moreover, the effect of mass ratio of nano-CaCO3 and micro-CaCO3 on the properties of PVC door and window profile in industry was studied. When the mass ratio was 2.5/9, the profile could obtain good mechanical properties.