Nondestructive Strategy to Effectively Enhance the Interfacial Adhesion of PBO/Epoxy Composites

Abstract

Low interfacial adhesion seriously limits the wide application of PBO fiber in composites. To solve this problem, a novel hierarchical reinforcement strategy was developed by introducing epoxy sizing, nanoreinforcement of amino-functionalized silicon dioxide (SiO 2 −NH 2 ), and an interfacial compatibilizer of 2,6-bis(2-hydroxy-4aminophenyl) benzobisoxazole (HABO) onto poly(p-phenylene benzobisoxazole) (PBO) fibers via a facile dip-coating approach. SiO 2 −NH 2 and HABO were uniformly dispersed in epoxy sizing, forming an active interface layer. On this basis, wettability, surface roughness of the PBO fiber, and compatibility with the resin matrix were significantly improved, which gave 88.4 and 40.4% enhancement in the interfacial shear strength and interlaminar shear strength of the corresponding composites, respectively. Moreover, it should be noted that the outstanding mechanical and thermal properties of the PBO fiber were not impaired during the sizing treatment. In summary, our work provides an effective and damage-free approach to improve the interfacial adhesion of PBO/epoxy composites.

Poly(p-phenylene benzobisoxazole) Fiber/Epoxy Composites Reinforced with Carbon Nanotubes and Graphene Oxide for Enhanced Interfacial Adhesion and Mechanical Strength

“…(ii) The grafted nanomaterials extend the interfacial region, especially the CNT stretched into the matrix provide the interfacial interaction with more mechanical interlocking . (iii) The open-ring reaction between the carboxyl and hydroxyl groups of carbon nanoparticles with epoxy groups creates massive chemical bonding for interfacial adhesion . (iv) Because of the strengthening effects of CNT and GO, the interfacial region has improved mechanical properties, structural complexity, and spatial coverage .…”

“…25 (iii) The open-ring reaction between the carboxyl and hydroxyl groups of carbon nanoparticles with epoxy groups creates massive chemical bonding for interfacial adhesion. 16 (iv) Because of the strengthening effects of CNT and GO, the interfacial region has improved mechanical properties, structural complexity, and spatial coverage. 24 Under the combined action of the above factors, the interfacial stress transfer and fracture energy dissipation become more effective, the stress concentration reduces or disappears, and the structural stability of interphase increases.…”

“…The storage modulus keeps a high value at the glassy state, decreases rapidly in the transition state, and then reaches a lower value at the plateau zone of the rubbery state. 16 This significant change of storage modulus is relevant to the segment motion of polymer molecules. The higher the temperature, the stronger the restriction for segment motion, the lower the storage modulus.…”

“…15 Among all technologies, grafting nanomaterials onto fiber surfaces to create a hierarchical or multiscale reinforcement is an effective and flexible method of obtaining advanced interfacial properties. 16 These nanomaterials grafting can increase the interfacial contact, enhance mechanical interlocking and local stiffening at the interfacial region, and improve load transfer capability and interfacial properties. 17 Meanwhile, the hierarchical reinforcements represent the additional energy dissipation mode that is conducive to the interlaminar fracture toughness.…”

“…The proposed strategies for interface control contain coating/deposition, , chemical grafting, plasma, and in situ synthesis . Among all technologies, grafting nanomaterials onto fiber surfaces to create a hierarchical or multiscale reinforcement is an effective and flexible method of obtaining advanced interfacial properties . These nanomaterials grafting can increase the interfacial contact, enhance mechanical interlocking and local stiffening at the interfacial region, and improve load transfer capability and interfacial properties .…”