Int. Journal of Applied Sciences and Engineering Research, Vol. 2, Issue 3, 2013 www.ijaser.com © 2012 by the authors – Licensee IJASER- Under Creative Commons License 3.0 editorial@ijaser.com Research article ISSN 2277 – 9442 ————————————— 242 *Corresponding author Received on May 2013; Accepted on May 2013; Published on June 2013 Biodegradability and Mechanical Properties of Low Density Polyethylene/Waste Maize Cob Flour Blends 1* H. C. Obasi, 2 G. C. Onuegbu 1,2 Department of Polymer and Textile Engineering, Federal University of Technology, Owerri, P.M.B 1526, Imo State, Nigeria. DOI: 10.6088/ijaser.020300007 Abstract: The properties of blend of low density polyethylene and waste maize cob flour (LDPE/WMCF) and maleated polyethylene (MAPE) as compatibilizer were studied. LDPE/WMCF composites with different filler loadings, with and without the addition of MAPE were prepared using a laboratory injection moulding machine. Mechanical properties of the LDPE were found to be worse when it was blended with the filler, due to the poor compatibility between the two phases. The addition of MAPE led to a much better dispersion and homogeneity owing to the formation of ester linkage group and thus showed better properties. Water uptake of compatibilized LDPE/filler composite (LDPE/WMCF) was lower than that of uncompatibilized LDPE/filler composite (LDPE/WMCF). Both composite were buried in the soil to assess biodegradability. Weight loss of composites observed indicated that both were biodegradable, even at high of filler concentration. Keywords: Low density polyethylene, waste maize cob flour, maleated polyethylene, mechanical properties, water absorption, biodegradability, composites and weight loss. 1. INTRODUCTION The emergence of plastics for the past few decades as alternatives to other traditional material such as paper, metals and ceramics for packaging and other applications has led to the increase in the production of plastics. This has exposed the universe to environmental problems because most of these materials are non-degradable and have remained in the refuse dumps and landfills for years. Efforts have been made to get rid of these problems through re-use and recycling but not all plastics are recyclable; incineration process is often used but these results in heat generation and causes air pollution. These situations contribute to serious environmental problems (Hanafi et al, 2011). Several researchers around the world now are engaged in synthesis of new polymeric materials and processes aimed at improving the environmental quality of a number of products (Singha et al, 2008; Kaith et al, 2008; Singha et al, 2008). The use of biopolymers has been considered alternative in reducing environmental problems. The main advantage of using biofillers is that these materials are biodegradable and renewable and exhibit low cost, low density and high stiffness. Nevertheless, the incompatibility between them and polymer matrix, the low dispersion degree of the fillers as well as their poor moisture resistance, generally results in decreased toughness (Klason et al, 1984; Dalvag et al, 1985) and lead to low performance materials, thus limiting their use. Polyethylene (PE) is a stable polymer, and consists of long chains of ethylene monomers. Polyethylene cannot be easily degraded with microorganisms. "However, it was reported that lower molecular weight PE oligomers (of Mw=600-800) was partially degraded by Acinetobacter sp.351 upon dispersion, while high molecular weight PE could not be degraded. The biodegradability of synthetic polymers like polyethylene can be enhanced by the addition of biodegradable additives to the formulation of plastics (Huang et al., 1990; Doi and Fukude, 1994, Potts, 1981). In plastics containing blends of PE with biofiller, microbes initially attack the filler resulting in an increase in the porosity and surface to volume ratio of the polymer blend and a consequent enhancement of its biodegradability. It has been shown that the increase in the filler content and decrease in the filler size enhance the biodegradability of the plastic blends (Lim et al, 1992, Peanasky et al., 1991, Zuchowska et al., 1998). Biopolymer, such as waste maize cob filler (WMCF) is a good example of degradable polymer that can be used to replace the hydrocarbon plastic material. The use of WMCF as reinforcing material for biodegradable composites can represent the conversion to industrially useful biomass energy.