The effect of chemical treatments on tensile strength and absorption ability of epoxy/natural fibers composites

Abstract

Natural cellulose from agricultural waste, fruit skin, stalks, and so on is considered as recyclable and may have some potential as oil and water absorbent. Besides it is readily available and environmentally friendly it also inexpensive because they are waste, non-toxic and biodegradable. However, the natural fibres are hydrophilic in nature, so it tends to absorb water. Chemical treatments can usually overcome this problem. Usually, acid and alkali treatments are very popular among researchers. In this study, we focused on seeing the differences in natural treatment on acidic and alkaline using citric acid (vinegar) and sodium bicarbonate (soda) of certain three types of selected fibres. The 24 hrs treatments were studied on coconut coir, banana stem fiber and sugarcane bagasse. The tensile strength has been investigated and compared. All fibers were observed highest tensile strength after treated with alkali compared to acid. Treatment with alkali is more suitable for natural fiber in order to clean the fiber surface, thus help to get better fiber-matrix interaction. These are the reason of highest in tensile strength. Overall, the absorption of oil and seawater depends on the type of fibre itself. All treated fibers tend to absorb more seawater and alkaline treated fibers absorbed more cooking oil. Treated coconut coir have tendency to absorb both medium than other fibers. The type of treatments, will give an effect on the fibres’ surface, remove the impurities and reduce the hydrophilic properties, so that provide decreasing or increasing of cooking oil and seawater uptake.