Preparation and properties of room-temperature-vulcanized silicone rubber using modified dopamine as a crosslinking agent

This paper investigates the modification of dopamine (IDA) and uses it as a crosslinking agent to enhance the mechanical strength and hydrophobicity of room-temperature-vulcanized (RTV) silicone rubber. IDA was successfully synthesized with dopamine and 3-isocyanatopropyltriethoxysilane. The structure of IDA was verified by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. IDA was introduced into the hydroxyl-terminated polydimethylsiloxane (PDMS) system to prepare RTV silicone rubber, and dibutyltin dilaurate (DBTDL) was used as the catalyst. A combination of the scanning electron microscope, thermal gravimetric analysis, universal testing machine, and contact angle was used to analyze the morphology and properties of RTV silicone rubber. The results demonstrated that the addition of IDA significantly enhanced the thermal stability and mechanical strength of RTV silicone rubber. The mechanical strength of the novel RTV silicone rubber increased by 221%. Moreover, the IDA modified RTV silicone rubber had better hydrophobicity as compared to the PDMS polymer prepared with the traditional crosslinking agent.