Studies on the effects of additives on the physico-mechanical properties of jute reinforced composites

Abstract

In this research work, different types jute reinforced polypropylene (PP) composites were prepared by injection moulding technique. To prepare improved jute-PP composites, different types chemical treatments were carried out. The effects of these treatments on the physico-mechanical properties of the composites were studied. Reaction parameters such as time, temperature, pH and concentration of coupling agents were investigated for all chemical treatments. Unbleached raw jute fibers were modified by sodium periodate oxidation and the effects of oxidized jute on the performance of oxidized jute reinforced PP composites were studied comparing with the raw jute-PP composites. Coupling reactions were carried out using urea and urotropine with the oxidized jute-PP composites by posttreatment processes. Fr-IR spectroscopic analyses were done for all chemical treatments and the results showed the evidence of positive reactions. The effects of urea and urotropine on the physicomechanical properties of the composites were studied. Maleic acid treatment was carried out on the raw jute-PP composites. The effect of maleic acid on the physico-mechanical properties of the composites was also studied. The effects of fiber content on the physicomechanical properties of composites were studied by preparing the composites with different percentage of fiber loading (from 20 wt% to 35 wt%) for each type of composites. Mechanical properties (tensile strength, tensile modulus, elongation at break, flexural strength, flexural modulus, charpy impact strength and hardness were measured for all treated composites and raw jute-PP composites. Improved mechanical properties were obtained for all the treated XXI composites over untreated raw jute reinforced PP composites. Scanning electron micrograph of the composites were taken to investigate the interfacial adhesion and bonding between the fiber and PP matrix resulting from the various chemical treatments. Improved interfacial interactions were found for treated composites than untreated composites. Water absorption tests were carried out of. all composites to investigate the effect of chemical treatment on the moisture absorption characteristic of hydrophilic jute in the jute-PP composites which has direct effect on the dimensional stability of the composites. Reduced water absorption was found for oxidized jute-PP composites, urotropine treated oxidized jute-PP composites and maleic acid treated raw jute-PP composites. All the findings are reported in details in this thesis.