空间质子与电子综合辐照作用下甲基硅橡胶破坏模型

利用空间辐照环境模拟设备对甲基硅橡胶进行了质子、电子综合辐照试验.质子、电子的辐照能量均为150 keV,辐照剂量均为10¹⁶ cm^-2.质谱测试发现,综合辐照过程中有CH₃Si(O)CH₃气体生成.量子化学计算表明,H⁺直接进攻硅橡胶高分子链中的氧而导致高分子链断裂的过程要放热655.34 kJ/mol,是唯一的放热反应通道.这一过程不会形成稳定的过渡态和中间体,而是直接形成断键产物.计算分析结果与综合辐照形成的气体产物CH₃Si(O)CH₃相吻合.

A Model for Destruction of the Methyl Silicone Rubber Net-structure after the Synergistic Radiation of Proton and Electrons

Synergistic radiation effect on methyl silicone rubber of protons and electrons was investigated using a ground-based simulator for space radiation environment. The energy of protons and electrons was chosen as 150 keV, and the fluence 10 16 cm -2. The gas product is CH 3Si(O)CH 3 by mass spectrum after synthesized radiation. The quantum chemistry calculation indicated that the macro-molecule chains in the silicone rubbers could be fractured by a direct attack of H + to the oxygen in the chains. This process was an only exothermic channel, giving out the heat of 655.34 kJ/mol. No stable transition states and intermediate products were formed, except for the fractured pieces of the chains. The calculation result was in agreement with the gas product CH 3Si(O)CH 3 formed by synergistic radiation of proton and electrons.