三元乙丙(EPDM)橡胶具有良好的化学稳定性、耐热氧老化、耐磨及电绝缘性能,高温工况时发生热解反应带走热量可形成碳化绝热层,在热防护领域有着广泛应用。考察硫化体系、填料种类和硫化工艺对三元乙丙橡绝热材料力学性能和压缩永久形变的影响。结果表明:当填充3份双叔丁基过氧化二异丙基苯(BIPB)作为硫化剂时综合性能最优,拉伸强度为11.7MPa,断裂伸长率为763%;在25℃下材料的压缩永久形变达到了22.22%,55℃下压缩永久形变为28.97%,70℃下压缩永久形变为28.42%。添加2份硫磺(S)时抗压变性能最优,在25℃、55℃和70℃下压缩永久变形16.85%、37.45%和35.29%。探究了几种补强填料在不同温度下对EPDM绝热材料压缩永久变形的影响,在填充白炭黑后力学性能达到了12.7MPa,625%的断裂伸长率,并且抗压变性能较好,白炭黑在25℃、55℃和70℃下压缩永久变形达到了15%、30%和52%,填充白炭黑的绝热材料烧蚀性能要更好,线烧蚀率低的同时还能保证碳层的坚固和完整性。

Ethylene propylene diene monomer (EPDM) rubber has good chemical stability,heat and oxygen aging resistance,wear resistance,and electrical insulation properties.EPDM is widely used in the field of thermal protection and when subjected to high-temperature,it undergoes pyrolysis reaction to take away most of the heat and form a carbonized insulation layer.This article investigated the effects of vulcanization system,filler type,and vulcanization process on the mechanical properties and compressive permanent deformation of EPDM rubber insulation materials.The results showed that when filled with 3 parts of bis (tert butyl) peroxide diisopropylbenzene (BIPB) as the vulcanizing agent,the comprehensive performance was optimal,with a tensile strength of 11.7MPa and a fracture elongation of 763%;The compression permanent deformation of the material reached 22.22% at 25℃,28.97% at 55℃,and 28.42% at 70℃.In the discussion of vulcanization additives,it was found that adding 2 parts of sulfur (S) resulted in the best compressive deformation performance,with compression permanent deformation of 16.85%,37.45%,and 35.29% at 25℃,55℃,and 70℃,respectively.We investigated the effects of several reinforcing fillers on the compression permanent deformation of EPDM insulation materials at different temperatures.After filling with silica,the mechanical properties reached 12.7MPa,and the elongation at break was 625%,along with good resistance to compression deformation.silica achieved compression permanent deformation of 15%,30%,and 52% at 25℃,55℃,and 70℃,respectively.The insulation material filled with silica had better ablation performance,lower linear ablation rate,while still ensuring the strength and integrity of the carbon layer.