甲基苯基乙烯基硅橡胶电离总剂量效应

甲基苯基乙烯硅橡胶具有耐高低温、防震等独特优势,在航天器的减震、密封等领域具有广泛应用前景。研究了甲基苯基乙烯基硅橡胶的电离总剂量效应。结果表明,随着辐射剂量的增加,甲基苯基乙烯基硅橡胶的力学性能出现了不同程度的退化。拉伸强度和撕裂强度变化规律以1×106 Gy(Si)剂量点为分界点。低于该剂量,拉伸和撕裂随剂量增加快速下降;高于该剂量时,随辐照剂量增加,拉伸强度出现一定程度反弹,呈现出宽"U"形,而撕裂强度则是先增加后下降。拉断伸长率和邵氏硬度A随辐照剂量增加分别出现快速下降和增加,最终接近饱和。最后,从辐射交联和裂解方面讨论了甲基苯基乙烯基硅橡胶电离总剂量效应的潜在物理机制。

Total ionizing effects of polymethyl phenyl vinyl siloxane rubber

Polymethyl phenyl vinyl siloxane rubber(MPVQ) has excellent performances of resistance of high or low temperatures and vibration abatement, etc., it should have spread application to spacecraft vibration abatement and seal. The total ionizing dose effects of MPVQ have been investigated. The results show that the mechanical properties have different degradation with the increase of the irradiation dose. The dose of 1106 Gy(Si) is the change point for the tensile strength and the tear strength. Lower than this dose, the tensile strength and the tear strength decrease quickly with the increasing dose. Higher than this dose, the tensile strength rebound slightly, presenting a wide U distribution; and the tear strength firstly increase and then decrease with the accumulated dose. The elongation at break and Shore A hardness quickly decrease and increase with the total dose respectively, and finally they are close to saturation. The underlying mechanism of total ionizing dose effects for MPVQ is discussed in terms of radiation crosslinking and radiation degradation.