Functionalization of Styrene-Butadiene Rubber and Skim Latex by Photo-Catalytic Reaction Using Nanometric TiO2 Film as a Photocatalyst

Functionalization of rubber latex is used to improve some weak properties. One method of functionalization is chemical modification by a photo-catalytic reaction. In this work, the functionalization of styrene-butadiene rubber (SBR) and skim latex were carried out under UV irradiation in the presence of TiO2 film, which was double spin-coated on a glass petri-dish, followed by calcination at 550°C. The structural characterization of functionalized rubber latex was analyzed by FTIR and NMR techniques. In the case of SBR latex, the hydroxyl group was observed after exposure to 80W of UV irradiation in the presence of H2O2 at concentration of 20% by weight of dry rubber. However, the gel formation derived from cross-linking as a side reaction obstructed the further characterization of microstructure and limited the applications of latex and solid rubber. In the case of skim latex, the effect of pH, H2O2 concentration and UV irradiation time were studied. It was found that the functionalization was successful after exposure to low power of UV irradiation for 1 h in the presence of H2O2 at concentration of 5-10% by weight of dry rubber. The weight-average molecular-weight (Mw) slightly decreased from 2x106 to 1x106 g/mol.