PLA-based plasticized nanocomposites: Effect of polymer/plasticizer/filler interactions on the time evolution of properties

Poly(lactic acid) nanocomposites containing calcium carbonate nanoparticles and two different low molecular weight plasticizers have been prepared by a two-step melt mixing process. Up to 9 wt% of nanoparticles were successfully added preserving the plasticity of nanocomposites and with beneficial effects on the elastic modulus and yield stress. Mechanical, thermal and transport properties were measured as a function of aging time, up to 20 weeks, to evaluate the phase evolution of the plasticized nanocomposites. An interesting improvement in the time stability of mechanical and transport properties was highlighted and related to the effect of particles/plasticizer interactions on phase structure.