Fragility of short?chain poly(lactic acid)s derivatives by combining dielectric spectroscopy and fast scanning calorimetry

Low-molecular-mass bio-polyesters, such as lactic acid oligomers, constitute a growing category of plasticizers for poly (lactic acid), since they show good compatibility and are respectful the environment. This study focuses on glass transition series oligomers with different molecular weights, aim investigating how their associated dynamics occur. Dielectric calorimetric results combined to mobility in large temperature range. In comparison exhibit lower fragility index smaller cooperative rearranging regions. Among is clearly dependent weight, whereas variations cooperativity subtler.