Effect of Silane Coupling Agent on the Curing, Tensile, Thermal, and Swelling Properties of EPDM/Mica Composites

Abstract

In this work, the influence of silane (bis (3-triethoxysilylpropyl) tetrasulfide) or Si69 coupling agent on properties of EPDM/mica composites was studied. Both EPDM/mica composites with silane and without silane were compounded using two roll mill at various filler loading (i.e., 100/0, 100/10, 100/30, 100/50, 100/70). The tensile and thermal properties as well as fracture surfaces of composites were tested using Instron Universal Testing Machine, Thermal Gravimetric Analysis (TGA) and Emission Scanning Electron Microscope (SEM). The results indicated that the optimum cure (t90), scorch time (ts2) value was lower, while maximum torque (MH) value slightly higher for EPDM/mica composites with silane compared to EPDM/mica composites without silane. The tensile properties, M100 and M300 value increased for EPDM/mica composites in the presence of silane and the optimum filler loading for those properties occurred at 50 phr. In addition, thermal stability and swelling ratio for both composites improved with increasing filler loading. However, EPDM/mica composites with silane show better thermal stability and swelling ratio due to stronger linkage taking place at the rubberfiller boundary and it promotes filler dis-agglomeration.