Studies on the physico-mechanical properties of chemically treated jute fibre reinforced plastic composites

Abstract

In this study, different types jute fibre reinforced polypropylene (PP) composites and test samples were prepared by single screw extruder and injection moulding machine respectively. To improve jute-PP composites, different types chemical treatment 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 every chemical treatments. Alkali bleached raw jute fibres were modified by sodium periodate oxidation followed by diazonium salt treatment. The effects of periodate oxidation and diazonium salt treatment on the performance of jute fibre reinforced PP composites were studied comparing with the raw jute fibre–PP composites. Coupling reactions were also carried out using para-nitroso N,N-dimethyl phenylamine. FT-IR spectroscopic analyses were done for all chemical treatments and the results showed the evidence of positive reactions. The effects of paranitroso N,N-dimethyl phenylamine on the physico-mechanical properties of the composites were also studied. The effect of fibre content on the physico-mechanical properties of the composites were studied by preparing the composites with different percentage of fibre loading(from 10%-35%) for each type of composite. Mechanical properties (tensile strength, Young modulus, flexural strength, flexural modulus and hardness were measured for all treated jute fibre and raw jute fibre-PP composites. Improved mechanical properties were obtained for all treated composites over raw jute reinforced PP composites. Scanning electron micrograph of the composites were taken to investigate the interfacial adhesion and bonding nature between the fibre and PP matrix resulting from the various chemical treatments. Improved interfacial interactions were found for treated composites than the untreated one. 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 treated jute-PP composites. Thermal analysis of the composite were carried out, which indicate better thermal stability of treated jute fibre –PP composite than the untreated one. Among the various chemical treatment sodium hydroxide bleached oxidized paranitroso N,N-dimethyl phenylamine treated jute-PP composites showed best mechanical and physical properties.