Novel approach for silane treatment of flax fiber to improve the interfacial adhesion in flax/bio epoxy composites

Abstract

Natural fibers have been approved as an excellent alternative for traditional reinforcements in polymer composites. However, the main disadvantage of natural fibers as reinforcements is their poor interaction with polymeric matrices due to their hydrophilic nature. In order to improve their compatibility as composite reinforcement, surface treatments are required. Silane treatment has been widely used to modify hygroscopic properties of natural fibers. In this study, a new method of silane treatment has been developed without the prehydrolysis and curing/dehydration of silanol groups. To do so, flax fibers were modified through 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO)-mediated oxidation followed by direct application of the amino-silane. The fiber/matrix interfacial adhesion was examined by measuring interlaminar shear strength. Thermogravimetric analysis and dynamic mechanical analysis were performed to study the thermal resistance and thermomechanical properties of the composites. The results revealed that fiber/matrix adhesion was improved in the oxidized silanized fiber composite. In addition, water absorption was significantly reduced (20%) in the oxidized silanized fiber reinforced composite compared with the as-received one.

Wear Performance of Value-Addition Epoxy/Breadfruit Seed Shell Ash Particles and Functionalized Momordica Angustisepala Fiber Hybrid Composites

“…The decreased in wax, hemicelluloses and impurities obtained could be attributed to the fact that the treatment of the fibers with OH-APS activates the O-H and hydrolyzable alkoxy group to formed silanols. A similar observation was obtained by Fath et al in the work [20,21].…”

“…This is in par with the work of the refs. [21,22]. In the EDS of Figure 5, the presence of Si in the OH-ASP treated MAf shows that the hydrolyzable alkoxy group formed silanols [22].…”

Natural Fibre Modification and Its Influence on Fibre-matrix Interfacial Properties in Biocomposite Materials

“…This could be due to the occurrence of interfacial slipping between the fibre and matrix caused by poor wetting of the fibres, which produces lower IFSS. Other studies also used the pull-out test and SEM to investigate the interfacial property and adhesion in natural fibre/polymer composites [19,[69][70][71]. It was concluded that natural fibre treatment significantly improved the adhesion between fibre and matrix, with a higher IFSS of treated composites during fibre-matrix debonding.…”

Dynamic Mechanical Behavior Analysis of Flax/Jute Fiber-Reinforced Composites under Salt-Fog Spray Environment

“…Another issue that contributes to a great extent to the low aging resistance of NFRPs under humid environmental conditions is the poor compatibility between hydrophilic natural fibers and several hydrophobic polymeric matrices such as epoxy resins [30,31]. In this regard, some researchers showed that the water resistance of natural fiber-reinforced polymer composites can be improved and their quasi-static mechanical properties under humid environment can be better retained through fiber chemical treatments [32][33][34][35].…”