Study of Process Parameters for Making Biodegradable Linear Low Density Polyethylene in Natural Weathering Conditions

The Objective of this project was to develop biodegradable and environmentally friendly polymers using starch blended with polyethylene (PE) by extrusion where starch content ranged between 0 and 15%. The samples of varying compositions were molded into plates and films. A portion of the specimens were exposed to sunlight and the rest buried underground. The deterioration of the starch-polyethlene composites following exposure was determined by measuring changes in tensile properties, flexural properties, SEM imaging and FTIR analysis of the samples. The mechanical properties of these samples were assessed to determine their feasibility as a packaging material. It was found that the addition of starch to the polyethylene decreases its tensile strength. Young’s modulus increased as a function of the amount of starch. Chemical structure was found degraded. Rate of degradation was different. Samples become very brittle and lose its strength within one month of exposure. SEM analysis revealed fractures and pores as a consequence of microorganism degradation. Pure PE samples however remained unchanged.