Thermal and Mechanical Properties of Biodegradable polyester/silica Nanocomposites

摘要

Nowadays, biopolymers have become more popular that is resulted from the growing concern on environmental issue and their enormous advantages. However, the application was limited by its thermal properties. Nanocomposite is one approach to increase the usability of biodegradable polymers. It is interesting to use this method for improvement the thermal stabilIty of polymer. Therefore, this work focused on the nanocomposites of biodegradable polyester. The nanocomposites of PLA, PBS and PHBV with hydrophilic fumed silica have been prepared by twin screw extrusion. The dispersion of silica particles in the polymer matrix was investigated by SEM technique. Thermal properties of samples were analyzed by TGA and HDT testing. The mechanical properties were also tested for tensile and impact testing. The results showed that the presence of silica nanoparticles increased the onset and inflection temperature of thermal degradation in PLA, PBS as well as PHBV nanocomposites. It showed the great improvement for PHBV nanocomposite. Similar to the HDT results, it was greatly improved from 140.0 °C for neat PHBV to 145.7 °C for PHBV/silica 5wt% nanocomposites. The mechanical performances of nanocomposites depended on the content and the dispersion of silica particles in the polymer matrix. At low silica content, the mechanical properties were slightly increased whereas the mechanical properties were worsen at the higher silica loading because of the agglomerate of silica in the polymer matrix.