Effect of alkalization on mechanical properties of green composites reinforced with cellulose from coir fiber

The natural fiber is basically composite material derived from nature, composed of a number of cellulose fibrils, bound by a matrix consisting of hemicellulose and lignin. Cellulose is the essential component of determining fiber strength, stiffness, and stability. This work focused to enhance the property mechanically of the coir fiber reinforced composites by increasing cellulose in fiber with alkali treatment. Coir fiber was treated with 5 %, 6 %, 7 % alkali (NaOH) for 4 h at room temperature. The treated coir fiber was used as reinforcing material to produce coir fiber-poly (lactic-acid) composites. In this experiment, the alkali treatment effect on tensile strength, tensile modulus, flexural strength and flexural modulus of the composites were studied and characterized. Results indicate an improvement in tensile dan flexural strength in alkali-treated composites. The highest value of tensile and flexural strengths are (40.01 ± 3.63) MPa and (47.72 ± 1.08) MPa respectively, for 4 h alkali treatment on the composites with 6 % alkali were supported by SEM (Scanning Electron Microscope) testing.