Zhang Hao, Tian Jinfeng, Yan Liwei, Zhou Shengtai, Liang Mei, Zou Huawei
The State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065, China.
Nanomaterials (Basel). 2023 Jan 30;13(3):563. doi: 10.3390/nano13030563.
The ablative properties of epoxy-modified vinyl silicone rubber (EMVSR) composites containing hexaphenoxycyclotriphosphonitrile (HPCTP) have been systematically studied. The strength of the ablation char layer was greatly enhanced with the addition of HPCTP, which induced the formation of a more complete, denser, and thicker char during oxyacetylene ablation tests. Moreover, the HPCTP-containing EMVSR composites demonstrated lower thermal conductivity and pyrolysis rate when compared with those without HPTCP. At the same time, the thermal insulation properties of HPCTP-filled composites were improved under low heat flow ablation scenarios. The reduction of graphitic carbon content, the formation of phosphate-like crystals as well as the increase of SiC content contributed to strengthening the char layer, which was critical for improving the ablation properties. The optimum char layer strength and thermal insulation properties were achieved when the content of HPCTP was 15 phr, whereas an optimum ablation resistance was achieved at 25 phr HPCTP. This suggests that HPCTP-modified EMVSR composites can be used for thermal protection purposes, especially in the fields of aerospace and aeronautics.
对含有六苯氧基环三磷腈（HPCTP）的环氧改性乙烯基硅橡胶（EMVSR）复合材料的烧蚀性能进行了系统研究。添加HPCTP后，烧蚀炭层的强度大大提高，在氧乙炔烧蚀试验中，HPCTP促使形成了更完整、更致密、更厚的炭层。此外，与不含HPTCP的复合材料相比，含HPCTP的EMVSR复合材料表现出更低的热导率和热解速率。同时，在低热流烧蚀情况下，HPCTP填充复合材料的隔热性能得到改善。石墨碳含量的降低、类磷酸盐晶体的形成以及SiC含量的增加有助于增强炭层，这对提高烧蚀性能至关重要。当HPCTP含量为15 phr时，炭层强度和隔热性能达到最佳，而当HPCTP含量为25 phr时，耐烧蚀性达到最佳。这表明HPCTP改性的EMVSR复合材料可用于热防护目的，特别是在航空航天领域。
