Processing And Characterization Of Walnut Shell Powder Filled Polyester Composites

Abstract

Due to generation of large volume of industrial, agricultural and biological wastages, disposal of these wastages now becomes a major challenge for whole world due to their harmful effect on the environment. So, waste management is the critical issue for the countries regarding collection transporting and disposal of these wastages. In this research, an agro-waste filler walnut shell powder (WSP) is used as filler material in polyester for composite making. This thesis has broadly four parts. The first part is about exploring the possibility of composite fabrication with walnut shell powder in polyester resin. This part also includes fabrication details of such composites along with its hybridization with short areca fibers as secondary reinforcement. The physical, micro-structural and mechanical characteristics of these composites are briefly discussed in the later part. The following part describes the theoretical models developed to predict effective thermal conductivity (Keff) of the polymer composites of the particulate filled and the hybrid composites. The evaluation of effective thermal conductivity, glass transition temperature coefficient of thermal expansion, dielectric and acoustic of these composites are discussed. The final part has reported about the experimental and analytical details on the sliding and erosion wear response of these composites. This report shows that successful fabrication of polyester composites filled with walnut shell powder and/or short areca fibers using solution casting technique is possible. The density and void fraction of the composites are greatly affected due to addition of WSP content. The tensile, flexural, compressive and impact strength of the composites also significantly influenced with the incorporation of the WSP filler. It is also observed that the thermal insulation capability of the composites is enhanced due to reinforcement of walnut shell powder and further improved by use of secondary short areca fibers. An improvement in glass transition temperature (Tg) and drop in coefficient of thermal expansion (CTE) of the composites is also reported with inclusion of walnut shell powder. At the same time, the walnut shell powder helps to improve acoustic insulation property of the composite. The dielectric constant of the composites shows an increasing trend with the reinforcement of both walnut shell powder. Correlations are developed and proposed for erosion and sliding wear rates with the independent process parameters by response surface method (RSM).From analysis of variance (ANOVA), the most significant factors affecting sliding and erosion wear rate of the composites are identified. The wear resistance capability of the composites is found to be improved by the incorporation hard walnut shell powder consisting of stone cells. The composites filled with walnut shell powder is found to be lower compared to that of composites consisting both walnut shell powder and short areca fibers.The developed composites have several advantages such low density, high mechanical strength, good corrosion resistance, low thermal conductivity, high resistance to wear and better sound absorption quality due to which these composites can be used in different domestic and industrial applications.