Impact of corona treatment on PLA film properties

This study unambiguously revealed that corona treatment led to modifications in both surface and bulk of PLA films. In particular, surface analysis displayed the well-known capability of corona treatment to chemically and physically modify the surface of PLA films at the nanometer scale by increasing polarity and roughness. The structural analysis displayed a slight increase in the crystallinity degree and slight modifications in mechanical properties of films. This probably originated from temperature increase associated to corona treatment, which favored physical changes (e.g. relaxation, crystallization) of a part of the bi-orientated PLA chains, and therefore highlights the importance of such an industrial step on the film properties for packaging applications. As a result of these modifications, the barrier properties of films to three gases (He, O2, CO2) are also slightly improved.