The erosion resistances of ethylene propylene diene monomer (EPDM) insulations are often inadequate for advanced solid rocket motor (SRM) applications. EPDM modification by blending secondary matrixes is a feasible approach to improve the ablative properties of EPDM insulations. The addition of flexible inorganic hybrid rubbers as a secondary matrix, such as silicones and polyphosphazenes, may impart EPDM insulations with better ablative performance. The blends of EPDM/hybrid rubbers represent the state-of-the-art heat-shielding materials for SRM. In the present work, methyl-phenyl silicone/EPDM and poly(diaryloxyphosphazene)/EPDM insulation systems with various blending ratios of secondary matrixes have been prepared. The ablative properties of the insulations were examined by oxy-acetylene ablation tests, and the results showed that these properties could be enhanced accordingly by blending with hybrid rubbers under appropriate proportions. The unique charred layers resulting from the hybrid rubbers contributed to their excellent ablation properties. For example, the silicone/EPDM insulations exhibited a more significant improvement of ablation resistance properties. With a 1:1 blending ratio of silicone/EPDM, the linear ablation rate was 0.06 mm s−1 after 20 s of oxy-acetylene ablation. The enhancement in the ablative resistance was attributed to the charred layers with bunches of embedded compact microtubes with a length of 2–3 mm, which consisted of silicon carbide, silicon dioxide, and Si–O–C ceramics.

中文翻译：

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由硅或聚磷腈混合弹性体改性的三元乙丙橡胶基隔热材料

乙烯丙烯二烯单体 (EPDM) 绝缘材料的耐腐蚀性通常不足以用于先进的固体火箭发动机 (SRM) 应用。通过混合二次基体对 EPDM 进行改性是提高 EPDM 绝缘材料烧蚀性能的可行方法。添加柔性无机杂化橡胶作为辅助基质，例如有机硅和聚磷腈，可以赋予 EPDM 绝缘材料更好的烧蚀性能。EPDM/混合橡胶的混合物代表了 SRM 的最先进的隔热材料。在目前的工作中，已经制备了具有各种二次基体混合比例的甲基苯基硅氧烷/EPDM 和聚（二芳氧基磷腈）/EPDM 绝缘系统。通过氧-乙炔烧蚀试验检查绝缘材料的烧蚀性能，结果表明，通过与混合橡胶以适当的比例共混，可以相应地提高这些性能。由混合橡胶产生的独特烧焦层有助于其出色的消融性能。例如，硅树脂/EPDM 绝缘材料在抗烧蚀性能方面表现出更显着的改进。使用 1:1 的有机硅/EPDM 混合比例，氧-乙炔烧蚀 20 秒后线性烧蚀速率为 0.06 mm s-1。烧蚀电阻的增强归因于炭化层具有成束的嵌入紧凑型微管，长度为 2-3 毫米，由碳化硅、二氧化硅和 Si-O-C 陶瓷组成。由混合橡胶产生的独特烧焦层有助于其出色的消融性能。例如，硅树脂/EPDM 绝缘材料在抗烧蚀性能方面表现出更显着的改进。使用 1:1 的有机硅/EPDM 混合比例，氧-乙炔烧蚀 20 秒后线性烧蚀速率为 0.06 mm s-1。烧蚀电阻的增强归因于炭化层具有成束的嵌入紧凑型微管，长度为 2-3 毫米，由碳化硅、二氧化硅和 Si-O-C 陶瓷组成。由混合橡胶产生的独特烧焦层有助于其出色的消融性能。例如，硅树脂/EPDM 绝缘材料在抗烧蚀性能方面表现出更显着的改进。使用 1:1 的有机硅/EPDM 混合比例，氧-乙炔烧蚀 20 秒后线性烧蚀速率为 0.06 mm s-1。烧蚀电阻的增强归因于炭化层具有成束的嵌入紧凑型微管，长度为 2-3 毫米，由碳化硅、二氧化硅和 Si-O-C 陶瓷组成。氧-乙炔烧蚀 20 秒后为 06 mm s−1。烧蚀电阻的增强归因于炭化层具有成束的嵌入紧凑型微管，长度为 2-3 毫米，由碳化硅、二氧化硅和 Si-O-C 陶瓷组成。氧-乙炔烧蚀 20 秒后为 06 mm s−1。烧蚀电阻的增强归因于炭化层具有成束的嵌入紧凑型微管，长度为 2-3 毫米，由碳化硅、二氧化硅和 Si-O-C 陶瓷组成。