Epoxy-silicone copolymer synthesis via efficient hydrosilylation reaction catalyzed by high-activity platinum and its effect on structure and performance of silicone rubber coatings

In this study, two different pre-polymers were obtained first through efficient hydrosilylation reaction by changing reaction time and catalyst dosage in the presence of polyoxyethylene epoxy resin (DEG-501) and hydrogen silicone oil with phenyl (UC-233), named EH-F and EH-L. And the chemical structure of pre-polymers was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance (¹H-NMR). Then the pre-polymers were incorporated into phenyl-containing silicone rubber at different mass fractions. Scanning electron microscopy observations demonstrated that a “sea-island” phase separation occurred obviously in the cured composites. Thermogravimetric analysis evaluation revealed that thermal stability of silicone rubber composites improved markedly after modification, the residual yield at 800 °C achieved 32.69% in the air atmosphere when 20 phr EH-F were introduced. And a degradation mechanism was discussed through elemental analysis and electronic images of char of silicone rubber systems. The mechanical properties results showed that tensile strength and shear strength of composites increased gradually with increasing EH pre-polymers. All of these results provide very valuable information for understanding hydrosilylation reaction and effects of molecular structures on performance of silicone rubber systems.