Towards a circular economy for PLA ? Technological, environmental and socio-economical aspects

Overview & Synopsis

Growing plastic consumption increases our dependence on non-renewable ressources as well as the quantity of waste. In this context, the development of biosourced and biodegradable polymers can open interesting perspectives to limit the impacts associated with petroleum-based polymers and on the dissemination of plastics in the environment. Therefore, the recycling of biobased materials in a circular economy perspective is an essential issue and a first objective of this work is to study the influence of successive thermomechanical cycles on color, thermal and mechanical properties of PLA. For this purpose, we have studied the influence of temperature and extrusion times on the thermal degradation of PLA to see to what extent we could valorize PLA having undergone several thermomechanical cycles with or without dilution in virgin PLA. In this perspective, in a first part, our work aims at "simulating" successive mechanical recycling, generally considered as the most impacting phases when recycling, to study their effects on the thermal, mechanical properties and visual aspect of PLA, that can be considered as indicators of the ability of a polymer to undergo mechanical recycling. Nevertheless, the suitability of end-of-life mechanical recycling of PLA and the socio-economic conditions of its implementation have to be considered. Thus, the second part will consist in a discussion on the socio-economic interest of the development of a PLA industrial recycling chain based on the approach developed in the first part.