Kamrul Hasan Bappy, M S Rabbi, Bishal Chakma
Natural fibers are increasingly being adopted as eco-friendly reinforcements in polymer composites due to their low cost, biodegradability, renewability, and widespread availability. In comparison with other lignocellulosic fibers, coconut petiole fiber available in tropical regions possesses superior mechanical properties and is one of the most widely used natural fiber for making composites. 5%, 10% and 15 wt.% fiber loadings using hand lay-up method. In order to facilitate fiber-matrix interfacial adhesion, the fibers were chemically treated using 5% sodium hydroxide (NaOH) treatment, which removed surface impurities such as lignin and pectin and enhanced both roughness of surface and crystallinity of the fibers. Mechanical properties such as tensile, flexural and impact were measured from the fabricated composites in addition to surface hardness and water absorption behaviors to assess their mechanical performance and moisture resistance respectively. The composite containing 10 wt.% fiber was found to have best performance in this case, with impact strength of 11520.24 J/m², flexural strength of 9.57 MPa, tensile strength of 11.09 MPa and Young’s modulus of 1330.1 MPa respectively. It was found that the Rockwell hardness of combined system (88.5-78 HRL) decreases with increased fiber loading, since the fibers are comparatively softer than that of or being softer than epoxy matrix. The water absorption was low for all the compositions, from 1.53% to 2.02%, and it shows that then fibers were well adhered to matrix and resistant to moisture penetration. The outcomes indicate that alkali modified coconut petiole fiber can be used as a green and effective reinforcement in engineering applications involving epoxy composites.