IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684, p-ISSN: 2320-334X. PP 43-45 www.iosrjournals.org National Conference on Advances in Engineering, Technology & Management 43 | Page (AETM’15)” Natural Fiber Reinforced Polypropylene Composites: A review Manpreet Singh Bahra 1 , Lakshya Aggarwal 2 , V.K.Gupta 3 1 (P.G. Student, Department of Mechanical Engineering, Punjabi University, Patiala- 147002, India) 2 (Associate Professor, M.M. University, Sadopur, Ambala, India) 3 (Professor, Department of Mechanical Engineering, Punjabi University, Patiala-147002, India) Abstract : Natural fiber reinforced composites, nowadays, are in great demand in industries because of their advantages such as low cost, biodegradability, acceptable mechanical properties and so on. Scientists and researchers prefer thermoplastic polymer matrix (polyethylene, polypropylene etc.) compared to thermosetting polymer matrix (epoxy, polyester, Bakelite etc.), reason being the low processing cost & high repair ability. Various natural fibers such as jute, flax, ramie, hemp, sisal, pineapple, cotton and many more are widely used as reinforcements in the polypropylene (PP) matrix and their mechanical properties were investigated by many researchers. Few of them are highlighted in the present paper. Keywords: Biodegradable material, Fiber reinforced composites, Natural fiber, Polypropylene. I. INTRODUCTION In the past decades, there is a growing trend of using natural fibers with the thermoplastic polymer matrix to prepare various composites. These are being used as an alternative to synthetic/man -made fiber reinforced composites. The advantages of natural fibers are environmental friendly, low cost, easy availability and bio-degradability. In natural fiber reinforced thermoplastic composites (NFRTC’s), the reinforcement is of natural fibers which can be jute, sisal, hemp, banana, cotton , bamboo, pineapple etc. embedded in the thermoplastic polymer matrix. These composites have received significant applications in automobile parts, window frames, household articles and toys. A number of investigations have been carried out to reveal the potential of natural fibers as reinforcement in thermoplastics. These studies showed positive results for NFRTC’s. Natural fiber reinforced polypropylene composites are made by combining natural fibers and polypropylene (PP). Polypropylene acts as a binder and is called the matrix which holds the reinforcement which is natural fibers. Natural fibers are the fibers which naturally comes from mineral, plant or animal having the advantages that they are renewable resources and good market appeal. These are mostly achieved from stems, leaves and seed of plants. On the other hand, polypropylene is a thermoplastic polymer which possesses several useful properties such as dimensional stability, transparency & flame resistance etc. The objective of the present paper is to provide a brief review of natural fiber reinforced polypropylene composites. II. REVIEW OF LITERATURE Natural fiber reinforced polymer composites are gaining popularity day by day because of the positive results showed by the researches towards them. Few of the past researches on natural fiber reinforced polypropylene composites are highlighted below. [1]kim et al. (2008) studied the mechanical properties of polypropylene (PP)/natural fiber composites. For the natural fiber component of the composites, cotton fiber was compared with wood fiber. In order to improve the poor interfacial interaction between the matrix and reinforcement, maleic anhydride (MAH) grafted PP (PP-g-MAH) was used as compatibilizer. The samples were fabricated using compression molding technique by taking three types of matrixes- H720P, H380P and H360 F with melting index 2, 25 and 12 g/10min. The results showed that tensile strength of PP/wood fiber composites decreased with increase in wood fiber loading, whereas, in PP/cotton fiber composites, it first decreases with 10 w. % fiber and then increases with 20 and 30 wt. % of cotton fiber. Flexural strength behavior was similar to that of PP/cotton fiber composites. Compatibilizer also had an effect on mechanical properties, for PP/cotton fiber (80/20 wt. %) and PP/wood fiber (80/20 wt. %) composites, tensile and flexural strengths were increased with increase in wt % of PP-g-MAH. [2]Ashori and Nourbaksh (2010) studied the effect of coupling agent (maleated polypropylene) and nanoclay particles on the mechanical properties and water absorption of the composites with PP as matrix and fresh poplar as reinforcement. For this, the composites were prepared using injection molding technique by fixing 30 wt. % of fiber while the concentrations for nanoclay and maleated polypropylene (MAPP) were varied