Preparation of High-performance Polyimide Fibers with Wholly Rigid Structures Containing Benzobisoxazole Moieties

• Published in: Chinese journal of polymer science Vol. 40; no. 3; pp. 280 - 289
• Main Authors: Fang, Yu-Ting, Gan, Feng, Dong, Jie, Zhao, Xin, Li, Xiu-Ting, Zhang, Qing-Hua
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.03.2022; Springer Nature B.V
• Subjects: Agglomeration; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Fibers; Industrial Chemistry/Chemical Engineering; Mechanical properties; Phenylenediamine; Polymer Sciences; Research Article; Rigid structures; Structural analysis; Tensile strength; Mechanical properties; Benzobisoxazole; Co-polymerization; Polyimide fiber; Microstructure
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-022-2666-8

In this work, a fully rigid coplanar symmetric heterocyclic unit was introduced into the rigid polyimide macromolecular backbone structure to prepare high-performance polyimide fibers. The novel co-polyimide (co-PI) fibers based on 3,3’,4,4’-biphenyltetracarboxylic anhydride (BPDA), p -phenylenediamine (PDA) and 2,6-(4,4’-diaminodiphenyl) benzo[1,2- d :5,4- d ’] bisoxazole (PBOA) were fabricated via a two-step wet-spinning method. The effects of benzobisoxazole moiety on spinnability, aggregation structure, and mechanical properties of fibers were systematically discussed. The detailed structural analysis revealed that the well-defined aggregation structures of co-PI fibers were obtained from initial amorphous structure when post hot-drawing temperature was higher than 460 °C under proper drawing ratio, and the incorporation PBOA into BPDA-PDA structures produced more compact structural co-PI fiber than homo BPDA-PDA fiber. The BPDA-PDA/PBOA co-PI fibers exhibited optimum tensile strength and modulus of 2.65 and 103 GPa, which increased by 182% and 84% compared to the homo BPDA-PDA fiber, respectively.