Thermal Degradation Behavior and Mechanism of Organosilicon Modified Epoxy Resin

Organosilicon modified epoxy resin is one of the most widely used ablative coating matrices in the whole aerospace industry. However, most research focuses on the final effect of organosilicon modification, while systematic studies on thermal degradation behavior and mechanism of organosilicon modified epoxy resin are rarely reported. In this work, a heat‐resistant epoxy resin (ES231) is prepared through the condensation reaction between epoxy resin and methylphenyl organosilicon intermediate. The TGA test results show that the integral procedural decomposition temperature (IPDT), the thermal residual weight at 800 °C (R800), and decomposition temperature range all improve under both N2 and air atmospheres after modification. The functional groups variation of polymers and the generated volatile segments during the degradation process are measured by FTIR, TG‐IR, and TG‐MS to investigate the thermal degradation mechanism in detail. Meanwhile, the composition and microstructure of the solid residue after thermal degradation are also systematically studied by SEM, XPS, and Raman spectroscopy. It is expected that this work can provide some theoretical basis and new ideas for designing new heat‐resistant epoxy resin. Heat resistant epoxy resin (ES231) is prepared by one‐step method. TG, FTIR, TG‐IR, and TG‐MS are used to investigate the thermal degradation mechanism in detail. The composition and microstructure of the solid residue are also systematically studied by SEM, XPS, and Raman spectroscopy. Thermal stability of resin is improved under both N2 and air atmospheres after modification.