231 American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) ISSN (Print) 2313-4410, ISSN (Online) 2313-4402 © Global Society of Scientific Research and Researchers http://asrjetsjournal.org/ Effects of Particle Size and Loading on Tensile and Flexural Properties of Polypropylene Reinforced Doum Palm Shell Particles Composites Samuel Audu Seth a* , Isuwa Suleiman Aji b , Aje Tokan c a,c Department of Mechanical /Production Engineering, Abubakar Tafawa Balewa University Bauchi, Nigeria b Department of Mechanical Engineering, University of Maiduguri Borno, Nigeria a Email: seth2audu@gmail.com b Email: suleimanaji@yahoo.com c Email: ajetokan@atbu.com Abstract Natural Particulates (fillers) are reinforcement in composite materials. They are used in matrix for cost reduction, improved processing, density control, thermal conductivity, control of thermal expansion, flame retardancy and improved mechanical properties. Doum palm shell particles reinforced composite was prepared by compounding polypropylene matrix with 10 - 40 wt. % Doum palm shell particles at 5 wt. % intervals for 150 μm and 300 μm particles sizes using compression moulding techniques. The effect of the particles size and particles loading on tensile and flexural properties of the composite produced were investigated. The results showed that the tensile strength increased from 34.12 MPa for neat polypropylene to a maximum of 44.88 MPa at 10 wt. % Doum palm shell addition for 150 μm particle size; while it increased to a maximum of 39.62 MPa at 10 wt. % Doum palm shell addition for 300 μm particle size. Flexural strength increased from 37.91 MPa for neat polypropylene to a maximum of 57.68 MPa at 10 wt. % Doum palm shell addition for 150 μm particle sizes; however, it increased to a maximum of 49.63 MPa at 10 wt. % Doum palm shell addition for the 300 μm particle size. 150 μm particle size composite yield a better result compared to 300 μm particles size which is in agreement with the literature, the smaller the particle size the better the properties of the composite because it has better compaction, reduced porosity which give effective stress transfer between the matrix and the particles. The use of doum palm shell as fillers in composite will not only provide a renewable source of filler in polymer composite but also generate a non – food source of economic development for the famers in the rural areas. Keywords: Doum palm shell particles; Polypropylene; Particle loading; Tensile and Flexural properties. ------------------------------------------------------------------------ * Corresponding author.