Synthesis of A Novel Cross‐linker with High Reactivity for Enhancing Compressive Strength of High‐performance Organic Fibers

Abstract

AbstractLow axial compressive strength of high‐performance organic fibers is one of the most prominent problems for their application in advanced technologies. In this paper, N, N’‐diphenyl‐1,4‐phenylacetyleneamide (DPAA) as a novel external cross‐linker was synthesized. It was confirmed that DPAA could react itself and quickly form cross‐linking network above 210 °C with pore width of 1–30 nm. Then DPAA was introduced into some typical high‐performance organic fibers through post‐swelling process, followed by annealing at 250 °C. It was found that DPAA would in‐situ form cross‐linking network inside the fiber, which was regarded as semi‐interpenetration structure. Compressive strength of Kevlar‐49 fiber modified through this method increased by nearly 70% and corresponding tensile strength didn't deteriorate. When PBO, heterocyclic aramid and polyimide fibers were modified by the same procedure, their compressive strength showed 25, 36 and 72% enhancement respectively. Therefore, DPAA is an effective modifier to enhance compressive strength of high‐performance organic fibers and shows great universality.