Effect of moisture susceptibility and aging on interlaminar fracture behavior of fumed silica reinforced Jute-Kevlar hybrid nanocomposite

This work aims to examine the influence of moisture uptake of fumed silica reinforced Jute (J)-Kevlar (K) hybrid composite on Mode I interlaminar fracture toughness. Mode I interlaminar fracture behavior is characterized by using the double cantilever beam (DCB) test specimen. Thirteen different composites are prepared based on four stacking sequences (i.e., Jute-Jute-Jute-Jute [JJJJ], Jute-Kevlar-Kevlar-Jute [JKKJ], Kevlar-Jute-Jute-Kevlar [KJJK], and Kevlar-Kevlar-Kevlar-Kevlar [KKKK]) and four nanofiller percentages (i.e., 0%, 1.5%, 3%, and 4.5%). Mode I fracture is experimented by using DCB test specimens. Mode I fracture energy (G(IC)) and Resistance curve (R-curve) is evaluated by using the modified beam theory (MBT) data reduction method at dry and wet conditions of the specimens. The interlaminar fracture surface of the composites is analyzed using an optical microscope. It is noticed that moisture ingression severely affects the fiber bridging, which is a key factor influencing the Mode I fracture resistance. The presence of fumed silica also plays a vital role by preventing the microcracks generation surrounding the fibers due to fiber swelling. The fiber swelling is caused by moisture ingression. The composite with stacking sequence JKKJ and 3% of nanofiller (JKKJ-3) is proved to be the reasonable Mode I fracture-resistant material in moist environment.