Comparison of the ablative performance of silicone rubber-based composites by analyzing a large number of samples

Abstract

Silicone rubber-based materials are important thermal protection materials for high-temperature applications. In this work, a holistic analysis of silicone rubber-based materials was conducted with an aim to comparatively study the ablative performance of different rubber matrices using the oxyacetylene flame. Six types of silicone rubber-based composites were prepared in large quantities using a customized device, and the relationship between the ablative properties and influencing factors was elucidated, which was useful in guiding the design and preparation of flexible ablative materials for thermal protection purpose. The expansion and ceramicization of char layer, which was realized by introducing expandable graphite and alumina was found helpful in reducing line ablation rate. The increase in the thickness of char layer and the decrease in surface roughness indicated a successful implementation of the above strategy, which led to a significant decrease in line ablation rate and an increase in thermal insulation performance of the studied system. Moreover, a thermal ablative composite with excellent moldability after ablation process was prepared which showed a promising application as a reusable thermal protection material. This work provided guidelines for developing flexible thermal ablative composites, which can be targeted for practical applications in aerospace and fire protection sectors.