Foam‐Forming Fabrication and Performance Study of Poly(p‐Phenylene Benzobisoxazole) Fiber Wet‐Laid Nonwoven Fabric Reinforced Polyimide Resin Composites

ABSTRACT In this work, Poly(p‐phenylene benzobisoxazole) (PBO) short fibers were rapidly fabricated into wet‐laid nonwoven fabrics using foam‐laying technology. The PBO wet‐laid nonwoven prepared via foam‐laying technology exhibited excellent uniformity, with a narrow pore size distribution and an average pore diameter of 74.15 μm. Various modified PBO wet‐laid nonwoven fabrics were prepared by co‐modifying PBO fibers with methane sulfonic acid (MSA) and 3‐aminopropyltriethoxysilane (APTES), then coating the nonwovens with cellulose nanometer whiskers (CNWs) at loadings of 1%, 0.1%, and 0.01%. Each of these modified nonwoven fabrics was subsequently impregnated with polyimide (PI) resin to fabricate PBO/PI composite materials. Surface modification introduced polar functional groups (hydroxyl and carboxyl) onto the PBO fiber surfaces, significantly enhancing wettability. Compared to the pristine PBO/PI composite, the sample containing 0.01 wt% CNWs exhibited a 24.3% increase in tensile strength, reaching 41.9 MPa, and the friction performance testing revealed a lower and more stable friction coefficient, while the wear volume increased by 23.8%. The prepared composite materials are applicable to fields requiring lightweight and high‐performance properties, such as the aerospace industry and automotive industry. Furthermore, the shorter preparation process can reduce production costs.