Mechanical, dynamic mechanical, and interfacial properties of sisal fiber-reinforced composite with epoxidized soybean oil-based epoxy matrix

In the present investigation, epoxidized soybean oil-based toughened epoxy composites were developed using unidirectional sisal fibers mat aligned at [0 degrees/0 degrees](s) and [0 degrees/90 degrees](s) orientations. Stiffness and strength of the [0 degrees/0 degrees](S) laminated composite are increased by 17% and 121%, respectively, as compared with the [0 degrees/90 degrees](s) oriented composite. Simialrly, Notched impact strength and critical strain energy release rate (K-IC) of [0 degrees/0 degrees](s) laminated composite were also highly improved by 19.5% and 33.4%, respectively, with respect to [0/90] laminated composite. Dynamic mechanical analysis of [0 degrees/0 degrees](s) oriented composite showed high storage modulus and broadened loss tangent curve revealing a strong influence of fiber orientation on damping behavior. The fibre-matrix adhesion in both the biocomposites is confirmed by scanning electron microgrphs of the impact fractured specimens. Contact angle and work of adhesion are measured to investigate the hydrophilic nature of epoxy, its blend, and composite toward water. POLYM. COMPOS., 39:2065-2072, 2018. (c) 2016 Society of Plastics Engineers