Lowering in water absorption capacity and mechanical degradation of sisal/epoxy composite by sodium bicarbonate treatment and PLA coating

In view of environmental imbalance due to numerous use of manmade fibers and plastic products, demand of natural fibers reinforced biocomposites have been increased. The products prepare by these biocomposites have been used in the various applications. However, their utilizations are not found suitable in the applications where high strength and high water resistance are required. The prime aim of the present study is to improve the water resistance capacity and mechanical performance of aged sisal biocomposites. In this context, hand lay-up process was used to prepare the epoxy-based biocomposites by reinforcing the surface modified sisal fibers consisted of eco-friendly sodium bicarbonate treatment and poly (lactic acid) coating. The highest water absorption, thickness swelling, and sorption, diffusion and permeability coefficients of the fabricated sisal composites were studied. Moreover, the effect of water absorption on tensile, flexural, impact, and hardness properties of the sisal composites was also investigated. It was noticed that treated and coated sisal composite revealed the best water resistant behavior than all other the composites. This composite exhibited 30% lower water absorption capacity than that of pure sisal composite. Further, lowest degradation in mechanical properties, that is, tensile strength (3.59%), flexural strength (33.18%), and hardness (11.96%) was observed for treated and coated sisal composite.