Cure Characteristics and Spectroscopic Studies of Silica Filled Epoxidised Natural Rubber Compound

Abstract

Reinforcement of rubber by precipitated silica is adversely affected due to lack of strong polymer filler bonding1-2. The surface energy of fillers play an important role in the reinforcement of rubbers and has a profound influence on the performance of rubber products3. Functionalised polymers interact strongly with surface silanol groups of precipitated silica. In this work, the unique reinforcement mechanism exhibited by silica in Epoxidised Natural Rubber (ENR) is established through rheometric and Fourier Transform Infrared Spectroscopic (FTIR) study. A rheometer torque rise was detected with an ENR compound silica in the absence of any curing agent. On the other hand, the extent of the interaction increased with the increment of epoxidation level. Fourier transform infra red spectroscopic studies showed silica is bonded to ENR through formation of Si-O-C bond and the extent of the chemical interaction depends on the moulding time4.