PREPARATION AND CHARACTERIZATION OF BAGASSE-WHEAT STRAW FIBER/ EPOXY BLENDED COMPOSITES

Abstract

Research in lignocelluloses materials is important because of their advantages over conventional reinforcing materials, namely, low density, high specific properties, non-abrasive nature, high level of filler loadings, high amount availability, renewability, safe working environment, etc. Because of low cost and good mechanical properties bagasse and wheat straw fiber is treated as most abundantly available fiber among all similar types of resources. It can be used as an effective reinforcing material with thermoplastic and thermosetting polymer. The present work, reports the experimental investigation on the development and characterization of blended natural fiber based composite along with bagasse and wheat straw fiber reinforced with epoxy. Initially composite made with the bagasse and wheat straw fibers reinforced with the epoxy resin separately and identify the optimum condition which gives a superior mechanical strength. Firstly, mechanical, thermal and water absorption properties of bagasse fiber reinforced epoxy composites has been studied. For this purpose, the epoxy resin is reinforced with 5, 10, 15, 20, and 25 weight % of the bagasse fiber with the help of a hand lay-up technique. Bagasse fibers are subjected to chemical treatment with 1 % sodium hydroxide followed by 1 % acrylic acid at ambient temperature to enhance the bonding strength between the fiber-polymer so as the results give high value of mechanical properties and reduces the water absorption properties of the composites. The optimum value of the bagasse fiber content are examined been found at 15 % treated fiber loading which gives better in mechanical properties simultaneously the lower in water absorption properties. Thermal analysis results prove that the treated bagasse fiber reinforced epoxy composites are 3 % more thermal stable than the untreated bagasse fiber/epoxy composites. Further, the feasibility of using wheat straw fiber with epoxy resin for developing the natural fiber-polymer composite has been studied. In order to improve the composite characteristic, wheat straw fibers are treated with three different concentrations of alkali (1, 3 and 5 %). The mechanical, thermal and water absorption properties of treated fiber composites are characterized and compared with untreated fiber filled epoxy composites. It is observed that the mechanical properties and water resistance are reduces with an increment in the wheat straw fiber loading from 5 to 25 wt %. Among the three levels of alkali treatment, composite made with 3 % alkali treated fiber exhibits superior mechanical and water absorption properties than the other treated fiber composite, which pointed to an effective fiber-matrix adhesion. The thermal properties of all composition of untreated and alkali treated wheat straw fiber ii reinforced epoxy composites are investigated. Upon analysis through Thermo Gravimetric Analysis (TGA) and Differential Thermal Gravimetric (DTG), it has been observed that the thermal stability of the high concentration alkali treated WSF/epoxy composite is 4 % superior to the untreated fiber composite. Finally, wheat straw fiber is blended with bagasse fiber. The wheat straw and bagasse fibers are prepared with various weight ratios (80/20, 60/40, 40/60 and 20/80) whereas total fiber content in epoxy matrix is 15 % and then incorporated into the epoxy matrix by molding technique to form composites. The mechanical, thermal and water absorption characteristics are examined using blended composite samples. In this part of work, it is found that an increases the bagasse fiber content in wheat straw/epoxy composites results that the 18 % increase in tensile strength, a 22 % increase in flexural and 46 % increase in impact strength. Epoxy resin reinforced with bagasse/wheat straw fiber composites proved to be the ideal low cost material with superior qualities. Raw material which were used in the present work is waste material and it is utilized in optimum manner which is not only cost effective but also helping the environment.