Effect of surface-modified TiO2 nanoparticles on the anti-ultraviolet aging performance of foamed wheat straw fiber/polypropylene composites

Abstract

Surface modification and characterization of titanium dioxide (TiO2) nanoparticles and their roles in thermal, mechanical, and accelerated aging behavior of foamed wheat straw fiber/polypropylene (PP) composites are investigated. To improve the dispersion of nanoparticles and increase the possible interactions between wheat straw fiber and the PP matrix, the surface of the TiO2 nanoparticles was modified with ethenyltrimethoxy silane (A171), a silane coupling agent. The grafting ofA171 on the TiO2 nanoparticles' surfacewas characterized by Fourier transforminfrared spectroscopy (FTIR). The wheat straw fibers treated with A171 and modified TiO2 nanoparticles were characterized by FTIR and thermogravimetric analysis (TGA). FTIR spectra confirmed that the organic functional groups of A171were successfully grafted onto the TiO2 nanoparticles andwheat strawfibers, and the modified TiO2 nanoparticles were adsorbed onto the wheat straw fibers. Thermogravimetric analysis showed that a higher thermal stability of thewheat strawfiberwas obtainedwith themodified TiO2 nanoparticles. The flexural, tensile, and impact properties were improved. A higher ultraviolet (UV) stability of the samples treated with modified TiO2 nanoparticles was exhibited by the study of the color change and loss in mechanical properties.