Biodegradable polymeric materials I. Polyethylene-natural polymer blends

Some composite materials susceptible to biodegradation processes were inves tigated on low density polyethylene (LDPE) and natural polymers based on st arch, lignin and dextrin. The amount of natural polymer was within the 0-30 % range in weight. The introduction and increase of the natural polymer con tent in the synthetic polymer utilized led to a decrease of apparent therma l stability of the starting polymer. The biodegradability tests achieved bo th "in vitro" (in the presence of Aspergillus niger and Trichoderma viride fungi) and "in vivo" (in the presence of a compost/sludge sewage mixture) e videnced that the susceptibility to biodegradation of the LDPE-natural poly mer blend increases with increasing the natural polymer content in the LDPE synthetic polymer.