Effect of surface modification of SiO2 particles on the interfacial and mechanical properties of PBS composites

In this study, WPU@SiO2 nanoparticles were obtained by grafting waterborne polyurethane (WPU) on the surface of silicon dioxide (SiO2). Then, WPU@SiO2 nanoparticles were introduced into the matrix of polybutylene succinate (PBS) to prepare a series of PBS/WPU@SiO2 composites. The dispersibility and interfacial compatibility of filler and matrix can be improved obviously by grafting a layer of WPU onto the surface of SiO2 nanoparticles. The FTIR and TGA results showed that WPU was successfully grafted onto the surface of SiO2. According to polarizing microscope images, it is clear that the size of the pure PBS crystals is much larger than that of the PBS/WPU@SiO2, and a large number of crystals are evenly distributed in the PBS/WPU@SiO2 composite. In addition, DSC and TGA results indicated that PBS/WPU@SiO2 composite films show excellent thermal properties. Meanwhile, the initial thermal decomposition temperature of PBS/WPU@SiO2 composite films is about 366-374 degrees C. For the 10 wt% WPU@SiO2 reinforced PBS-based composite films, the tensile strength reached the ultimate value (38.49 MPa), which is 32.04% higher than that of pure PBS. Based on its excellent mechanical and thermal properties, the PBS/WPU@SiO2 composites have a broad application prospect in the field of biodegradable materials.