Abstract
The ring-opening reactions (ROR) of epoxide groups in epoxidized natural rubber/titania (ENR-50/TiO2) hybrid in potassium hydroxide/isopropanol medium were examined using NMR spectroscopy and supported by the FTIR technique. The thermal behaviour of the hybrid was also studied using TG/DTG and DSC analyses. The H-1 NMR results suggested that 16.82% of ROR occurred in the hybrid, while the C-13 NMR results exhibited five new peaks at delta 19.5, 71.0, 73.7, 91.7 and 94.4 ppm in the hybrid. 2D NMR, such as HMQC, HMBC and COSY techniques, further scrutinized these assignments. The FTIR spectrum exhibited Ti-O-C characteristics via the peak at 1028 cm(-1). The TG/DTG results showed four steps of thermal degradation at 44-148, 219-309, 331-489 and 629-810 degrees C due to the existence of Ti moieties along with a polymer chain mixture (intact and ring-opened epoxide groups) of ENR-50, which in turn led to an increase in the T-g value of the hybrid to 27 degrees C compared to that of purified ENR-50 at -17.72 degrees C. (C) 2018 Production and hosting by Elsevier B.V. on behalf of King Saud University.