B 4 C P /PI聚酰亚胺复合薄膜耐高温及热中子辐照屏蔽性能研究
摘要
B<sub>4</sub>C<sub>P</sub>/PI polyimide composite films with different powder contents and thicknesses were prepared by particle surface modification and wet mixing machinery-thermal imidization method, using high temperature polyimide as matrix and micro-sized boron carbide (B<sub>4</sub>C) as thermal neutron absorption material. The thermal neutron radiation shielding property, thermal stability and mechanical property of B<sub>4</sub>C<sub>P</sub>/PI polyimide composite films were mainly discussed in this paper. It is shown that the micro-sized B<sub>4</sub>C functional particles can be well dispersed in PMDA-ODA polyimide matrix, and the thermal stability of B<sub>4</sub>C<sub>P</sub>/PI polyimide composite films are significantly improved with the increase of B<sub>4</sub>C content. However, the mechanical properties of the composite films present the opposite trend; meanwhile, the B<sub>4</sub>C<sub>P</sub>/PI polyimide composite films exhibit excellent thermal neutron radiation shielding properties, and the neutron permeability I/I<sub>0</sub> presents exponential relationship with the increasing thickness of composite and B<sub>4</sub>C filler particle content. Therefore,through structural design of the materials,the applications requirements in different fields for materials with high temperature resistant and thermal neutron radiation shielding properties can be met.