Rational design and preparation of the modified polyimide copolymer with superior anti-gamma irradiation

Abstract

To improve polymer-based bonded solid lubricating materials with excellent anti-gamma irradiation performance, a polyimide (BPI, Polyimide containing hexafluoropropane 2,2-bis(3-amino-4-hydroxyphenyl)diamine monomer) copolymer containing phenolic hydroxyl and trifluoromethyl groups was synthesized based on a conventional two-step method. Comparative studies have been conducted to investigate the effects of gamma irradiation on microstructure, thermal stability, mechanical and tribological properties under the different irradiation dose conditions. The results show that, compared with the pure polyimide (PI) and corresponding coatings, the modified BPI copolymer and coatings have better gamma-ray irradiation resistance duo to the copolymer contains lots of the activated phenolic hydroxyl groups and fluorine, which could be effectively inhibit the active destruction of parts of chain structure of copolymer, resulted in the BPI copolymer and BPI based coatings possess good comprehensive mechanical and tribological properties after 1000 kGy gamma irradiation. This study provides a novel approach for the design and preparation of lubricating coatings for nuclear energy systems.