Journal of Minerals and Materials Characterization and Engineering, 2016, 4, 228-240 Published Online May 2016 in SciRes. http://www.scirp.org/journal/jmmce http://dx.doi.org/10.4236/jmmce.2016.43021 How to cite this paper: Usman, M.A., Momohjimoh, I. and Gimba, A.S.B. (2016) Effect of Groundnut Shell Powder on the Mechanical Properties of Recycled Polyethylene and Its Biodegradability. Journal of Minerals and Materials Characteriza- tion and Engineering, 4, 228-240. http://dx.doi.org/10.4236/jmmce.2016.43021 Effect of Groundnut Shell Powder on the Mechanical Properties of Recycled Polyethylene and Its Biodegradability Mohammed Awwalu Usman 1* , Ibrahim Momohjimoh 2 , Abdulahi S. B. Gimba 3 1 Department of Chemical Engineering, University of Lagos, Lagos, Nigeria 2 Department of Metallurgical Engineering, Yaba College of Technology, Lagos, Nigeria 3 Skilia Resources Ltd., Abuja, Nigeria Received 2 March 2016; accepted 27 May 2016; published 30 May 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Natural fiber reinforced composites have gained considerable attention particularly in the manu- facturing industry owing to their light weight, corrosion resistance, abundance, and biodegrada- bility. In this work, alkaline treated and untreated groundnut shell powder (GSP) was used to rein- force recycled polyethylene to produce GSP-recycled polyethylene composites with improved me- chanical properties and biodegradability. GSP with particle sizes of 0 - 300 µm and 300 - 600 µm was used in different proportions: 5%, 10%, 15%, 20%, 25%, and 30% wt. The fiber was im- mersed for 5 hours in a 10 wt% NaOH solution. Tensile and hardness test data showed an im- provement in mechanical properties of the treated fiber composites. Results of water absorption test also showed that treated GSP-recycled polyethylene composites had a lower rate of water ab- sorption than the untreated GSP-recycled polyethylene composites. Through Fourier transform infrared spectroscopy, disappearance of characteristics peaks of hemicellulose and lignin was ob- served. Growth of fungi on the fiber-reinforced composites was observed, which was evidence that GSP-recycled polyethylene composite was biodegradable. Finally, SEM micrographs showed uni- form distribution of treated fibers in the polymer matrix; this explained the observed improvement in the mechanical properties of treated GSP-recycled polyethylene composites. Keywords Groundnut Shell Powder, Fibers, Recycled Polyethylene, Composites, Mechanical Properties, Biodegradability * Corresponding author.