Surface Modification of Bamboo Fibers to Enhance the Interfacial Adhesion of Epoxy Resin-Based Composites Prepared by Resin Transfer Molding

Abstract

Bamboo fibers (BFs)-reinforced epoxy resin (EP) composites are prepared by resin transfer molding (RTM). The influence of BFs surface modification (NaOH solution or coupling agents, i.e., KH550 and KH560) on interfacial properties of BFs/EP composites is systematically investigated. The synergistic effect of hydrolysis, peeling reaction of BFs, and the condensation reaction of hydrolyzed coupling agents are confirmed by FTIR. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) reveal that the interfacial compatibility of NaOH- and silane-modified BFs/EP composites was significantly improved. KH550-modified BFs/EP composite renders optimal tensile, flexural, and impact strength values of 68 MPa, 86 MPa, and 226 J/m. The impact resistance mechanism at the interface of BFs/EP composites was proposed. Moreover, the dynamic mechanical properties, creep behavior, and differential scanning calorimetry of BFs/EP composites have also been carried out to understand thermal stabilities. Overall, the surface-modified BFs-reinforced EP composites exhibited superior interfacial bonding.

Effect of Diisocyanates as Compatibilizer on the Properties of BF/PBAT Composites by In Situ Reactive Compatibilization, Crosslinking and Chain Extension

“…It was reported that various modification methods aiming at overcoming the incompatibility and refining the interfacial adhesion between polymer and fiber, include chemical modification of bamboo-powder surface or the addition of appropriate compatibilizer, and the latter was the most effective way to overcome two-phase incompatibility [12,[16][17][18][19]. The most used in situ reactive compatibilizers to compatibilize PBAT and natural fibers contain epoxy or diisocyanate groups, which could easily form chemical bonds between both PBAT and natural fiber [20][21][22][23].…”

Potential of Using Amazon Natural Fibers to Reinforce Cementitious Composites: A Review

“…The physicochemical characteristics of the interface are responsible for the mechanical properties of the composite as a whole. However, both interface and interphase help with the mechanical properties of the composite material, the main one being the adhesion of the material [ 104 ].…”

“…When electrostatic attraction occurs between the matrix and the reinforcement, electrical charges are transferred from one to the other, leading to the formation of a negative charge on one substrate and a positive charge on the other. This generates an electrostatic attraction between the composite components [ 104 ]. Chemical adhesion is given by bonds of the electronic structure during the formation of the interface.…”

“…One of the most effective techniques for investigating the distribution, adhesion and compatibility between the reinforcement and the composite matrix is scanning electron microscopy (SEM). It is one of the most commonly used ways to analyze the interfacial interaction between reinforcement and matrix, which leads to a positive effect on both tensile and shear strengths [ 104 ]. As an example, Figure 3 shows the SEM micrograph of a fiber-reinforced composite showing the effect of fiber bonding and the compaction of the interfacial transition zone (ITZ), as indicated by Fediuk et al [ 111 ].…”

Interfacial reinforced carbon fiber composites inspired by biological interlocking structure

“…To solve weak interfacial adhesion of existing CFRCs, various approaches for surface modification of CFs were extensively investigated ( Prakash and Rajadurai, 2017 ; He et al., 2021 ; Dai et al., 2011 ; Andideh and Esfandeh, 2016 ; Wang et al., 2019 ; Chukov et al., 2019 ; Sun et al., 2020 ; Sepe et al., 2018 ; Nie et al., 2017 ; Hu et al., 2018 ; Huan et al., 2020 ; Zhu et al., 2017 ; Zhang et al., 2020b ; Fu et al., 2019 ). The main purpose of these strategies is to improve the interfacial bonding strength between fibers and the matrix by providing more physical contact for mechanical interlocking, thereby creating rich active groups or good wettability for chemical bonding ( Karnati et al., 2020 ; Raphael et al., 2018 ; Sharma et al., 2014 ).…”