Enhancing interfacial adhesion and mechanical performance ofPBOfibers composites through mussel‐inspired molecular regulation of interphase structure

Abstract

Poor interfacial properties are always one of the bottleneck problems limiting the development of the PBO fiber/epoxy composites. To solve this, we demonstrated a mussel-inspired molecular regulation strategy of interphase structure using the layer-by-layer construction of rigid (PDA) and flexible (PEI) molecules without fiber structure damage. The precise control on the molecular scale can maximally increase the roughness and polar functional group on the fiber surface, thus enhance the chemical bonding and the mechanical interlocking of the interfacial adhesion. In comparison with the untreated fiber, the IFSS and ILSS value of fiber with (PDA/PEI)n have an increment of 86.85% and 80.08%, respectively. Besides, the overall mechanical performance, such as impact strength and dynamic thermal-mechanical behavior, was also improved significantly, owing to the improved physical-mechanical attributes of the interphase. In brief, our study presents a non-destructive interface regulation of PBO fiber composite to enhance its interfacial adhesion and mechanical performance and optimize its structure/function integrated design.

Preparation and Interfacial Properties of Hydroxyl-Containing Polyimide Fibers

“…For nearly a century, many efforts have been concentrated on developing high-performance synthetic fibers for hi-tech industrial applications, due to the outstanding characteristics of fiber-reinforced polymer matrix composites (FRPs), such as low weight, high ratio of tensile strength to weight, excellent stiffness, and versatile designability [ 1 ]. For example, carbon fibers (CFs) have been maturely applied to the composites of aircraft and automotive fields; ultra-high molecular weight polyethylene (UHMWPE) fibers with outstanding specific absorption energy are widely utilized as reinforcement in bulletproof and stab-proof composites; and poly-p-phenylene benzobisoxazole (PBO) fibers with excellent mechanical–thermal properties have become an ideal reinforcement for composites in aerospace, military, and transportation fields [ 2 , 3 , 4 ]. Unfortunately, these facts, including the brittleness of CFs [ 5 ], the low glass transition temperature of UHMWPE [ 6 ], and the non-UV resistance of PBO [ 7 ], limit the use performance, application fields, and service life of such composites to some extent.…”

“…Compared to other aromatic fibers, such as Kevlar ® , M5 ® , and Zylon ® [ 4 , 21 , 22 ], aromatic PI fibers possess copious designability of the molecular chain structure, i.e., the introduction of specific groups into the polymer main chain to improve the comprehensive properties of the fibers, such as 2-(4-aminophenyl)-6-amino-4(3H)-quinazolinone (AAQ), 2-(4-aminophenyl)-5-amino-benzimidazole (BIA), 5-amino-2-(2′-hydroxy-4′-aminophenyl)-benzoxazole (HBOA), 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB), p -phenylenediamine ( p -PDA), etc. In detail, Niu et al [ 23 ] designed and synthesized an aromatic heterocyclic diamine AAQ containing the -NH- group, which was incorporated into the BPDA/ p -PDA molecular backbone.…”

Pipeline Processing via the Combination of Heat and Corona Treatments for Improving the Poly(p-phenylene benzobisoxazole) Fiber Surface and Anti-Aging Performances

“…11,12 Thus, surface modification plays a vital role in the improvement of the interfacial interactions between PBO fibers and resins. methods, involving surface modification PBO fibers via chemical modification, 13 plasma modification, 14,15 coronadischarge modification, 16 surface constructing modification, 17,18 coupling-agents medication, γ-ray irradiation, 19,20 etc. 21−23 Heat treating is a common method to enhance the elastic modulus of organic fibers; meanwhile, the PBO fibers after the heat treatment(recorded as PBO-HT fibers) can possess a high modulus.…”

“…Therefore, applications for PBO fibers in high-performance conditions were limited. , Thus, surface modification plays a vital role in the improvement of the interfacial interactions between PBO fibers and resins. Many researchers have attempted to improve the interfacial interactions between PBO fibers and epoxy resins by different methods, involving surface modification PBO fibers via chemical modification, plasma modification, , corona-discharge modification, surface constructing modification, , coupling-agents medication, γ-ray irradiation, , etc. − …”

Enhancement of interfacial properties of HMCF composites by constructing of rigid‐flexible interphase through naphthalenediimide with different flexible chain lengths

“…With the increase of PnBA flexible chain length, the thermal residual stress at the interphase gradually decreased, whereas IFSS was initially increased and then decreased, which implied smaller thermal residual stress but weaker interfacial adhesion due to the presence of excessive PnBA flexible chains. [19][20][21] Baris Demir et al grafted single and double amine-terminated phenyl ring molecules onto the surface of CF, respectively, proving more amino groups determined the larger IFSS due to stronger covalent interaction between amine-bearing molecular and epoxy resin. 22 In view of the interphase construction by NDI selfassembly as modulus intermediate layer in HMCF composites, the NDI rigid-flexible copolymer with different flexible side chains and number of amino groups could be designed by introducing the substituents at N-imide and core positions.…”