Bio- and photo-degradation of natural fiber reinforced starch-based biocomposites

Biocomposites of starch and natural fibers were produced by compression molding. Potato, sweet potato, and corn starch were used as matrices of the biocomposites. Natural fibers including jute, sisal, and cabuya were used as discrete reinforcement. Water, glycerol, glycols, and a chitosan solution were used as plasticizers. Biodegradation was studied using both a compost chamber and a spore solution in an agar-based culture medium. Weight loss was recorded at specific time intervals for the tests of biodegradation in a compost chamber. Microscopical analysis was used to assess biodegradation in agar medium. Photodegradation was studied in a UV degradation chamber. Weight loss was also recorded at specific time intervals. All the biocomposites displayed similar degradation patterns under compost. During the first seven days a marked water absorption tendency was dominant in the weight variation curves. After that period, weight loss became more evident. In the case of UV degradation, a large part of the recorded weight loss was due to a drying effect due to IR radiation and took place mainly during the first seven days. This was taken into account in order to determine the net effect of UV degradation on weight loss.