Biodegradation study of a starch and poly(lactic acid) co-extruded material in liquid, composting and inert mineral media

The biodegradation of a co-extruded starch/poly(lactic acid) polymeric film was studied in liquid, inert solid and composting media. Main mechanical properties of this film were Youngʹs modulus: 2340 MPa, elongation at break: 50%, contact angle: 118°. Mineralization of the materialʹs carbon content was followed using the appropriate experimental methods of the International Standard Organisation. Whatever be the biodegradation medium used, the percentage of mineralization was better than the required 60% value for the definition of a biodegradable material. Moreover, repartitioning of the materialʹs carbon between the various degradation products produced was quantified throughout the duration of experimental runs. The presence of starch was found to facilitate biodegradation of the polylactic component, especially in liquid media.