Insights into the reinforcement and mechanism of silicone mold rubber co-modified with WCB and MMQ resin

Abstract

The exploitation of condensation room-temperature vulcanized silicone rubber (C-RTV) with excellent mechanical properties and thermal stability is of great practical significance in the preparation of insulation materials and rubber products with high performance. In this work, novel silicone rubber was fabricated successfully by adding white carbon black (WCB) and different percentages of methyl MQ (MMQ) silicone resin to C-RTV silicone mold rubbers (C-RTV/WMMQ). The mechanical properties, dimensional thermal stabilities, and thermal decomposing temperatures of the as-prepared samples were investigated in detail. Compared to the primitive C-RTV, the tensile strength of the sample with the WCB adding an amount of 15% increased from 0.44 MPa to 3.9 MPa. When the 1% MMQ was introduced, the tensile strength further increased to 4.4 MPa, suggesting a 12.8% reinforcement rate in addition to the improvements in the dimensional thermal stabilities and decomposing temperature. Based on the experimental results, a feasible synergistic effect and compatibility mechanism was proposed that hydrogen bond formed on the interface between MMQ resin and C-RTV in addition to the rigid structure of WCB, and thus led to a dense crosslinking network structure in the polymer matrix.