International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 08 Issue: 03 | Mar 2021 www.irjet.net p-ISSN: 2395-0072 © 2021, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 1406 Mechanical Properties of Natural Fibre [White Madar] Reinforced Polymer Composites V.Ajith 1 , Dr.P.K.Palani 2 1 PG Scholar in Manufacturing Engineering,Government college of Technology ,Coimbatore,Tamilnadu, INDIA. 2 Professor, Department of Mechanical Engineering Government college of Technology ,Coimbatore, Tamilnadu, INDIA ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract - Natural fibers play a very imperative role in the development of bio-degradable composites to fix the current environmental problems. In this investigation, the feasibility of applying renewable and eco-friendly white Calatropis gigantea fiber, composite as an alternate is studied.These extracted fibers are characterized by SEM, The chemical analysis indicates that white Calatropis gigantea fiber has significant cellulose content (69.65 wt. %) and less density (558 kg/m 3 ). The average crystalline index (CI) is observed as 56% and the morphological as well as surface roughness parameters justified that the white Calatropis gigantea fiber promotes significant bonding strength, while it is used as reinforcement in polymer composites. Various samples are prepared, tensile, compression and flexural tests are carried out. The results indicate that Calatropis gigantea fiber has better properties compared to glass fibre. Key Words: Bio-degradable composites;Calatropis gigantea fiber; Bonding strength; Crystalline index; Polymer composites. 1. INTRODUCTION Composite is a structural material that consists of two or more constituents that are combined at macroscopic level and are not soluble in each other. The idea of combining several components to produce a material with properties that are not attainable with the individual components has been used by man for thousands of years. Almost all the material which we see around us is a type of composite. Natural fibres in simple definition are fibre's that are not synthetic or manmade. They can be sourced from plants or animals. The use of natural fibre from both resources, renewable and non-renewable such as oil palm, sisal, flax, and jute to produce composite materials, gained considerable attention in the last decades, so far. The plants, which produce cellulose fibres can be classified into bast fibres (jute, flax, ramie, hemp, and kenaf), seed fibres (cotton, coir, and kapok), leaf fibres (sisal, pineapple, and abaca), grass and reed fibres (rice, corn, and wheat), and core fibres (hemp, kenaf, and jute) as well as all other kinds (wood and roots. Advanced composites comprise structural materials that have been developed for high technology applications, such as airframe structures, for which other materials are not sufficiently stiff. In these materials, extremely stiff and strong continuous or discontinuous fibres, whiskers, or small particles are dispersed in the matrix. A number of matrix materials are available, including carbon, ceramics, glasses, metals,and polymers. Arthanarieswaran,[1] describes the evolution of five water soluble phenol resin as binders at 5 percent concentration, for oriented and random reinforced bagasse composite. They tried to determine the amount of resin retained during processing when these phenolics were precipitated on to bagassefiber. Madhu.,P.,M.R.Sanjay [2] tries to use the sugar cane bagasse waste as reinforcement to polymeric resins for fabrication of low cost composites. They reported that composites with homogeneous microstructures could be fabricated and mechanical properties similar to wooden agglomerates can be achieved. Kumar, R.,N. Rajesh Jesudass.[3] in their work reported the processing and properties of bagasse fiber- polypropylene composites. Four different chemical treatments were done on fiber to improve interface adhesion with the thermoplastic matrix namely isocyanine, acrylic acid, mercerization and washing with alkaline solution. Their result shows that the best results were obtained on materials with treated fibers. A.Kumaravel and S.S.Saravanakumar. [4, 5] have converted the bagasse into a thermo formable material through esterification of the fiber matrix. The dimensional stability and mechanical properties of the composites prepared from the esterifies fibers were reported in this work.Balasundar,P.[6] analyzed the impact strength and hardness of sugarcane bagasseresol composites and showed that impact strength increased and hardness diminished as the fiber volume fraction increased. Kommula,V.P[7] used short sugar cane fibers as reinforcement to obtain fiber reinforce composites. Lignin extracted from sugarcane bagasse was used as a partial substitute of phenol (40w/w) in resole phenolic matrices.They characterized the composite by mechanical tests such as impact, DMTA and hardness tests. The results as a whole showed that it is feasible to replace part of phenol by lignin in phenolic matrices without loss of