Compounding and processing of biodegradable materials based on PLA for packaging applications: In greening the 21st century materials world.

Poly(lactic acid) is a well known polymer for more than 20 years in the biomedical fieldsapplications. Today, according to rising prices of oil and massive consumption of fossil resource,this biodegradable aliphatic polyester is on the way to be a wide used commodity polymer.Moreover PLA is as a “green plastic” because it is synthesized from annually renewable resources.In many ways similar to poly(ethylene terephtalate) such as rigidity, transparency, crystallizationkinetics and food contact ability, it fulfills the packaging industry requirements for most of the rigidobjects. But for applications like hot food packages, soft films and stretch blow bottles for examplesome properties of PLA have to be improved like heat deflection temperature (HDT), impactstiffness and gas barrier properties. There are many ways reported in literature today to improvethese properties. In order to compare it with other well known polymers, figure 1 representsthermal properties of PLA and these polymers. The aim of the work deals to identify actualweaknesses of commercial grades of PLA. Secondly, to present pertinent ways to improve PLA‟sproperties have been identified according to chosen process and final properties wished. This studyis composed of three main items. In a first time, a bibliographical study is necessary to identify thedifferent ways to improve PLA‟s properties used by researchers and industrials in literature. Themost significant ways will be describe here. Then PLA compound (PLA with additives or PLAcopolymers for examples) will be synthesized in conditions closed to industrial conditions studyingcrystallisation kinetic and rheological properties. In this step thermal, physico-chemical andmechanical properties of products synthesized will be characterized. At the end of this study thebest ways of improving PLA‟s behavior will be presented and describe