Soil Burial of Polyethylene-g-(Maleic Anhydride) Compatibilised LLDPE/Soya Powder Blends

This study examines the production of linear low density polyethylene (LLDPE)/soya powder blends to be used as alternatives to cellulosic material/polyolefin blends. LLDPE was blended with soya powder in a Haake internal mixer by melt mixing. Composition of the soya powder was varied from 5wt% to 40wt%. Polyethylene grafted maleic anhydride (PE-g-MA) was used as a compatibiliser. Environmental degradation was evaluated by composting the blends sample into the soil. It was found that for a higher soya powder composition, the degradation rate increased. Blends with compatibiliser degraded at lower rates than the uncompatibilised blends. The carbonyl indices of uncompatibilised blends subjected to the soil burial test were found to be higher than compatibilised blends. The weight loss changes in time data was collected and used to estimate the further changes by curve-fitting method. The complete degradation of the blends can be estimated from the kinetic curve. DSC results indicate that the crystallinity of the blends increased with increasing soya powder content added after composting.