DIFFERENTIAL SCANNING CALORIMETRY STUDY OF PLASTICIZED POLY(LACTIC ACID) FILMS DURING AGING

V.P.MARTINO; R.A.RUSECKAITE; A. JIMENEZ

Alicante (España)

Conferencia; 1st International Conference on Biodegradable Polymers and Sustainable Composites; 2007

Poly (lactic acid) (PLA) is one of the main biodegradable aliphatic thermoplastic polyestersand it has been extensively investigated during the last decades as an alternative to polymers based onfossil resources (1). It shows many physical characteristics that make it suitable for rigid containers but in order to obtain flexible films, it must be plasticized (2). In general, home–made plasticizers were specifically synthesized and showed good performance at least for concentrations lower than a critical value beyond which phase separation could be observed (1,2). In a previous work, PLA was successfully plasticized with three commercial polyadipates for concentrations lower than 20wt.% (3). However, some plasticizer migration was visually observed with time. PLA films may suffer aging during storage, which may change some physical and mechanical properties during the use-life of such materials. Particularly, aging may favour plasticizer migration and this is a very important issue to be considered in food contact polymers.