Modified silica to strengthening and toughening soft polyvinyl chloride

Abstract Modifying nanoparticles for polymer nanocomposites is important for multifunctional and low‐cost developmental direction. However, nanoparticles have several deficiencies, such as dispersion, agglomeration, and poor binding ability with most polymers. This work used soft polyvinyl chloride (PVC with 33.1% plasticizer volume) as the matrix. Polycaprolactone (PCL) was synthesized on the surface of SiO 2 by the bridging effect of silane coupling agent (SiO 2 ‐PCL), which was expected to improve the bond strength between SiO 2 and soft PVC matrix. Moreover, it enhanced the dispersion of SiO 2 in the PVC matrix. The results revealed that SiO 2 ‐PCL was nanodispersed in a soft PVC matrix and played a plasticizer role in the composite, which enhanced the tensile strength and elongation at break of PVC composites. The thermal stability and solvent extraction stability of PVC composites elevated with the increase of SiO 2 ‐PCL content. When the content of SiO 2 ‐PCL was 8 wt%, the tensile strength (14.54 MPa) and elongation at break (149.47%) of PVC composites were the highest, 64.36% and 60.48% higher than those of unfilled PVC, respectively. It was indicated that PVC composites were dramatically toughened and strengthened by modified SiO 2 , improving their overall performance.