Processing and characterization of betel nut and textile fiber reinforced hybrid polypropylene composites

Abstract

In the present work hybrid composites were manufactured by using hot press machine incorporating 2, 3 and 4 layers of natural (e.g. areca) and textile (e.g. nylon) fibers at constant fiber loading of 10 wt.% . Consequently areca fiber was treated by 5% NaOH. Composites were also prepared at four levels of fiber loading (5, 10, 15 and 20 wt %) with fiber ratios of (treated areca: nylon=1:1) , (treated areca: nylon=3:1) , (treated areca: nylon=2:3) , (treated areca: nylon=3:2) and (treated areca: nylon=3:2) for 20% fiber loading. The tensile, flexure and hardness tests were conducted for mechanical characterization of composites. Tensile strength, Young's modulus, %EAB, flexural strength, flexural modulus, shore hardness values enhanced with the increase of number of fiber layers. Interestingly tensile strength and % elongation at break showed a decreasing trend with the amount of fiber content in the composites. On the other hand Young’s modulus and flexural properties increased up to a certain level and hardness exhibited an increasing trend with the increase of fiber content. Notably all these mechanical properties enhanced with increasing nylon fiber content except tensile strength. In addition 5% NaOH treatment of the areca fiber provided an improving trend of properties of the composites. The Fourier Transform Infrared spectroscopy was carried out of the composites to study the effect of alkali treatment which showed decrease of hemicelluloses content. Scanning Electron Micrograph imaging of tensile fracture surfaces of all the composites were carried out to examine the variation in failure modes and to investigate the interfacial adhesion and bonding between fiber and PP matrix, in this case 4 layers of fibers containing matrix showed favorable entanglement between fibers and matrix. Thermo Gravimetric analysis showed slight enhancement of thermal stability after alkali treatment. These composite can be used in manufacturing automotive parts such as various panels, shelves, trim parts and brake shoes.