Preparation and characterization of chemically modified Jute–Coir hybrid fiber reinforced epoxy novolac composites

Abstract

In this study, the effects of fiber surface modification and hybrid fiber composition on the properties of the composites is presented. Jute fibers are cellulose rich (>65%) modified by alkali treatment, while the lignin rich (>40%) coconut coir fibers consist in creating quinones by oxidation with sodium chlorite in the lignin portions of fiber and react them with furfuryl alcohol (FA) to create a coating around the fiber more compatible with the epoxy resins used to prepare polymer composites. The maximum improvement on the properties was achieved for the hybrid composite containing the jute-coir content of 50 : 50. The tensile and flexural strength are recorded as 25 and 63 MPa at modified coir fiber content of 50 vol %, respectively, which are 78% and 61% higher than those obtained for unmodified fiber reinforced composites, i.e., tensile and flex-ural strength are 14 and 39 MPa, respectively. The reinforcement of the modified fiber was significantly enhanced the thermal stability of the composites. SEM features correlated satisfactorily with the mechanical properties of modified fiber reinforced hybrid composites. SEM analysis and water absorption measurements have confirmed the FA-grafting and shown a better compatibility at the interface between chemically modified fiber bundles and epoxy novolac resin. Hailwood-Horrobin model was used to predict the moisture sorption behavior of the hybrid composite systems.

Fabrication, Characterization, and Evaluation of Luffa cylindrica Fiber Reinforced Epoxy Composites

“…There is substantial epoxy matrix adhering to the fiber surfaces; indicating that the interfacial bond strength is fairly high due to little difference in surface energies between the fibers and the matrix. These results are in accordance with the findings in our previous research work where we analyzed the improvement of the mechanical properties of jute, coir, and bagasse fiber reinforced epoxy novolac composites by modification of the fiber surface (Saw and Datta 2009;Saw et al 2011Saw et al , 2012.…”

“…The tensile properties of the composite were influenced by the strength and modulus of the fibers as reported in Table 5. Chemical treatment of the fiber improved chemical bonding and helped it to withstand high tensile load by the composites made of them (Sabeel and Vijayarangan 2008;Saw et al 2012). The extent of improvement in mechanical properties for FA-grafted fiber reinforced composites was higher than that observed for alkali treated fiber composites.…”

Static and Dynamic Mechanical Analysis of Coir Fiber/Montmorillonite Nanoclay-Filled Novolac/Epoxy Hybrid Nanocomposites

“…The first step was involved in the formation of novolac resin through condensation of phenol and formaldehyde under oxalic acid catalyzed with the molar ratio of phenol to formaldehyde was 1:0.8. In the second step, the epoxidation of previously prepared novolac resin was carried out by reacting novolac with excess of epichlorohydrin with 1:8 molar ratio under 40 % sodium hydroxide catalyst (Saw et al 2011b(Saw et al , 2012. The schematics of synthesis are shown in Fig.…”

An overview of structural-functional-integrated composites based on the hierarchical microstructures of plant fibers

“…Initially, PFRCs by using non-woven forms of plant fibers were developed in automotive sectors given their low density, low cost, and environmentally friendly characteristics to these parts [4]. Manufacturers, however, have since learned that these materials offer both structural and damping benefits [5][6][7]. This may render them an economical alternative to glass fiber-reinforced composites (GFRCs) for quasi-structural or structure-functionintegrated applications in some critical sectors such as those of aircraft and ground transportation [8][9][10][11].…”