A green UV-resistant Natural rubber-Polydopamine-TiO2@SiO2 composite with high mechanical properties based on an electrostatic adsorption effect

Abstract

Abstract Antioxidants are usually added into the natural rubber (NR) to resist the oxidation caused by the ultraviolet (UV) irradiation, while commonly used antioxidans are usually organic and prone to decomposition and migration. The inorganic UV absorbers like titanium dioxide nanoparticles (TiO2) and silicon dioxide (SiO2) can maintain chemical stability under UV radiation, while the hydroxyl radicals from electron-hole pairs in TiO2 would damage NR matrix and the poor compatibility of TiO2 with NR limited the process. Therefore, inert SiO2 is coated on TiO2 (TiO2@SiO2) to reduce its photocatalytic activity, and polydopamine (PDA) is coated on rubber to improve stability. The strong light-absorbing properties of PDA could also improve the UV-resistant ability of NR. Besides, poly (sodium-p-styrenesulfonate) (PSS) coating NR-PDA provides the matrix negative charge, and polydiallyl dimethyl ammonium chloride (PDDA) wrapped around TiO2@SiO2 can give a positive charge, thus moderating the compatibility between the filler and the matrix through electrostatic adsorption. The green UV-resistant natural composite NR-PDA TiO2@SiO2 was fabricated. The composites exhibited strong tensile strength and excellent UV-resistant properties, which particularly extend the service life of rubber products as UV-shielding materials, thus showing significant potential in extreme environments.