BROMINATION OF NATURAL RUBBER WITH N-BROMOSUCCINIMIDE

ABSTRACT The mechanism of bromination of natural rubber (NR) was studied by solution-state 1 H-NMR spectroscopy. The bromination of NR was carried out at 20–50 °C with N -bromosuccinimide as the brominating agent, and the kinetic study of bromination was conducted under nitrogen atmosphere at 30–50 °C for various reaction times. The influence of bromine atom substituent on the bromination rate constant ( k ) also was investigated. Bromine atom content was found to be dependent upon the reaction time, indicating first-order kinetics. The activation energy of bromination of NR, calculated from the reaction rate constants, was 19.3, 5.5, and 5.8 kJ mol −1 for bromine atom linked to carbon atom with methylene proton and methylene protons, respectively.