Thermal Neutron Radiation Shielding and Thermal Properties of B₄C_P/PI Polyimide Composite Films

Abstract

B4CP/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 (B4C) as thermal neutron absorption material. The thermal neutron radiation shielding property, thermal stability and mechanical property of B4CP/PI polyimide composite films were mainly discussed in this paper. It is shown that the micro-sized B4C functional particles can be well dispersed in PMDA-ODA polyimide matrix, and the thermal stability of B4CP/PI polyimide composite films are significantly improved with the increase of B4C content. However, the mechanical properties of the composite films present the opposite trend; meanwhile, the B4CP/PI polyimide composite films exhibit excellent thermal neutron radiation shielding properties, and the neutron permeability I/I0 presents exponential relationship with the increasing thickness of composite and B4C 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.

Keywords

• polyimide
• boron carbide
• thermal neutron radiation shielding
• thermal stability
• mechanical property