Abstract:
Polymeric materials are increasingly used to replace numerous metallic components due to their advantageous qualities such as increased strength-to-weight ratio and corrosion resistance. However, because polymers are not biodegradable, their extensive use creates an environmental problem. In this study, the ability of epoxy composites made with 5 wt% waste jute fiber and 5 wt% waste sawdust fiber to biodegrade was examined when exposed to drain water for one year and the mechanical properties and fracture morphology of the as-cast and weathered samples were inspected to evaluate the biodegradation. The composites comprising 5 wt.% jute fiber and 5 wt.% sawdust experienced a reduction in tensile strength by 57% and 40%, respectively, because of biodegradation caused by microorganisms present in the drain water. All other mechanical properties, including flexural strength, toughness values, and hardness of the composites, were also dropped, indicating degradation in the composite samples in drain water. During the weathering period, weight gain was initially detected due to the water absorption by the porous fibers, however, after three months, the composites began to lose weight due to fiber deterioration caused by swelling and microbial attack. Microorganisms in the drainage system have used the fiber as an energy source, causing the fiber to deteriorate and producing CO2. The CO2 emissions from weathered composite samples were determined using FTIR analysis as a new peak emerged at the 1700 cm-1 wavenumber, representing the C=O group. TGA examination of the as-cast and weathered samples showed that the onset of the thermal degradation temperature of the weathered composites has decreased as a result of degradation. SEM imaging was utilized to identify fiber disintegration caused by the microbial attack, as well as fiber swelling produced by water absorption in jute and sawdust fibers has also been identified through SEM imaging. The SEM image reveals the formation of biofilms and the growth of microorganisms at the fiber surfaces. The microorganisms grew faster in the jute fiber composite than in the sawdust fiber composite, because sawdust includes a high degree of lignin, which protects against degradation. The findings of this investigation indicate that both sawdust fiber and jute fiber composites promote biodegradability in the epoxy matrix, but jute fiber was more prominent. The finding suggests the possibility of utilization of waste natural fibers to accelerate the degradation process of polymer-based materials and contribute to reducing the polymer-related pollution in the environment.