Effect of Epoxidation Level in Silica Filled Epoxidized Natural Rubber Compound on Cure, Rheological, Mechanical and Dynamic Properties

Reinforcement of rubber by precipitated silica is adversely affected due to lack of strong polymer silica bonding. Functionalized polymers interact strongly with surface silanol groups of precipitated silica. In this work, the effect of variation of epoxide content in silica filled Epoxidized Natural Rubber (ENR) compound was studied namely ENR 10, 25, 37.5 and 50mol%. Increasing in epoxide level of rubber has contributed to a better rubber filler interaction and lead to better mechanical properties. Meanwhile, ENR's with a greater degree of polarity has contributed significantly to higher storage moduli at small deformation and also leads to increase in bound rubber content value. Fourier transform infrared spectroscopy studies show that silanol groups in silica interact with ENR through the formation of Si-OH bond.