HIGH-STRENGTH AND HIGH-MODULUS POLYIMIDE FIBER AND PREPARATION METHOD THEREFOR

摘要

A high-strength and high-modulus polyimide fiber and a preparation method therefor, which are in the technical field of high-performance organic fibers. The fiber comprises a polyimide fiber prepared from biphenyltetracarboxylic dianhydride (BPM), p-phenylenediamine (pPM) and 2-(4-aminophenyl)-5-aminobenzimidazole (BIA), wherein the molar ratio of PPDA and BIA is 1:10 to 3:1; during the synthesis, other diamine monomer or dianhydride monomers can be added, and during the preparation, a gradient temperature reaction process and a one-step continuous preparation process are adopted, thereby overcoming the difficulties in synthesis and processing caused by increase of the content of 2-(4-aminophenyl)-5-aminobenzimidazole, and solving the problem of poor homogeneity and stability of the fiber performance. As a result, a high-strength and high-modulus polyimide fiber is obtained. The strength can be up to 4.5 GPa, and the modulus can be up to 201 GPa. Moreover, the sources of the raw materials are wide, the spinning process is continuous, the cost is low, and the efficiency is high, thereby achieving industrial production.