Modification and characterization of technical bamboo fibers and their polypropylene based composites

Abstract

This research work attempted to propose a new technique for characterization of bamboo fiber as reinforcement in composite. Raw bamboo fiber was characterized by thermal, structural and mechanical testing.The tensile properties (tensile strength, strain to failure and Young’s modulus) of raw bamboo fiber were studied by varying span length. FTIR spectroscopic analysis was done for observing the bonding in raw bamboo fiber. For determination of cellulose, hemicellulose, lignin, ash etc chemical analysis was conducted. TGA analysis was analysed for observing thermal stability. Degree of crystallinity, crystalline index and microfibril angle were measured using XRD peak analysis. Surface and cross-section of bamboo fiber were observed under SEM. For bettermechanical propertiesraw fiber was modified physically and chemically. The raw bamboo fiber was treated physically with different doses of gamma radiation. In physically modified sample, degradation temperature was increased with increasing the radiation. But after obtaining the optimization, temperature was found to decrease. For chemical treatment waste chemical liquor from leather industry was used. Leather industry waste chemical liquor, containing mimosa, BCS and syntan, was used for fiber modification. Physical and chemical modifications have improved the mechanical, chemical and physical properties of fiber. FTIR spectroscopic analysis was done for treated sample and resultsshowed the evidence of reaction with bamboo fiber and chemicals. In chemical analysis process, no significant change was observed. Crystallinity index and degree of crystallinity was found to improve with modifications. Fiber surface was found to be smooth and this was due to change of surface energy. Among all modified samples doubly treated fiber, treated with basic chromium sulphate and NaHCO3 (BCS+NaHCO3), showed best results. BCS+NaHCO3 treated fiber was selected as reinforcing agent for fabrication of composites withpolypropylene matrix using hot press moulding machine under specific pressure and temperature. The effect of fiber content on the mechanical properties was studied by preparing the composite with different percentage of fiber loading. The tensile properties were found to improve in modified fiber than the raw fiber based composite. Images of the fiber and fracture surfaces into the composites were taken to examine the failure mode and to investigate the interfacial adhesion between the fiber and matrix.