Biodegradable polymer blends based on polyethylene and natural polymers. Degradation in soil

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