Biodegradable Polymer Blends Based On Polyethylene and Natural Polymers. Degradation in Soil

Blend films based on low-density polyethylene and various natural polymers, namely, non-modified and chemically modified wood flour, starch, lignin and dextrin were exposed to soil over periods of 6, 12 and 24 months. The mechanical properties, the weight loss, the water absorption, as well as the thermal behaviour of the samples exposed to soil were evaluated. Biodegradation of the polyethylene/natural polymer blends is influenced by the nature of the natural polymer used, the capacity of the samples to water absorption, as well as by the duration of exposure in soil. Incorporation of the natural polymer in polyethylene is associated with a decrease in the mechanical properties of polyethylene, and with an increase in the susceptibility to biodegradation in the environment.