A study on the morphology and mechanical properties of PVC/nano-SiO2 composites

Three methods were used to modify nano-SiO2 particles with various interfaces and interfacial interactions between the particles and Poly(vinyl chloride) (PVC) matrix. The experimental results show that direct surface treatment of nano-SiO2 particles with a silane coupling agent (KH-550) is not effective for improving the mechanical properties of PVC/SiO2 composites. Both ultrasonic oscillations and high energy vibromilling improve the interfacial interactions between SiO2 particles and PVC matrix. With these methods, the aggregation of SiO2 particles was inhibited and a good dispersion of SiO2 particles in PVC matrix was obtained, which improved the mechanical properties of the PVC/SiO2 composite. The mechanical properties of the PVC/SiO2 composite with high energy vibromilling modified SiO2 particles were remarkably improved. Scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), dynamic mechanical analysis (DMA), and theoretical calculations demonstrate these improvements.