A study on mechanical and thermal behavior of coir fiber reinforced epoxy composites

Abstract

The main focus of this study is to utilize the properties of natural fibers and make them compatible with polymer resins effectively. Coir fibres have been used as reinforcement in epoxy resin with various weight percentages of 5%, 10% and 15%. Surface treatment method like alkali treatment is done to improve the performance of coir fibre on epoxy resin. Cow dung powder is added as filler to the composite with a purpose of improving the insulation property of the composite. The mechanical properties like tensile strength, flexural strength, impact strength and the micro hardness showed an increment with respect to fibre loading as well as the alkali treatment. The maximum value is found with the composite having 15% treated coir fibre. Flexural strength showed maximum value at 10% treated fibre loading which decreases after 10% fibre loading. When fibre loading was increased, thermal conductivity reduces. By adding cow dung powder to the untreated fibre composite, thermal conductivity is further decreased. From Thermo Gravimetric Analysis (TGA) it is found that the surface treated fibre composites resist the thermal decomposition effectively up to 2600C after that there is a considerable increase in the thermal stability. Differential Scanning Calorimetry (DSC) showed that the specific heat capacity increases with increase in fibre loading. Untreated fibre composites showed better specific heat capacity than the treated ones. Cow dung powder added to the untreated composite showed that maximum specific heat and specific heat capacity increases further to higher values as the quantity of cow dung powder is increased. Glass transition temperature (Tg) showed an increment with surface treatment as well as fibre loading of up to 10% and after that it decreases