Multiplying Tensile Strength of RTV Silicone Rubber via Fiberglass & Kevlar Plies Reinforcement

This work attempted to improve tensile strength of room temperature vulcanized (RTV) silicone rubber (SR) by plies reinforcement. Reinforcement was carried out using single layer of Kevlar or fiberglass ply laid in between SR utilizing a specialized molding process. Prior to that, compatibilization process was done using 3-9 (methoxylyl) methacrylate and hexyltrimethoxysilane to improve the continuous-dispersed phase adhesion. Then, the SR composites were subjected to tensile test and thermal gravimetric analysis (TGA). The results indicate that the reinforcement improved the tensile strength, where Kevlar/SR at 23 MPa and fiberglass/SR at 13 MPa were $8 \times $ and $5 \times $ greater than just plain SR, respectively. By comparison, higher tensile strength was recorded with Kevlar than that of fiberglass by 70%. This enhancement owed to a more uniform and distributed loading between the SR matrix to the plies, supported by the decent interfacial adhesion. The incorporation of such plies, however, resulted in slightly lower thermal stability for the SR, indicating minor incomplete curing. Overall, the successful reinforcement process of RTV SR with the plies not only widens its application in high-performance application, but also eliminates the need for expensive manipulation of SR monomer.