Thermoplastic starch/polyvinyl alcohol blends modification by citric acid–glycerol polyesters

Abstract

The first step towards the production and marketing of bioplastics based on renewable and sustainable materials is to know their behavior at a semi-industrial scale. For this reason, in this work, the properties of thermoplastic starch (TPS)/polyvinyl alcohol (PVA) films plasticized by a green solvent, as the 1-ethyl-3-methylimidazolium acetate ([Emim+][Ac􀀀]) ionic liquid, produced by melt-mixing were studied. These blends were prepared with a different content of [Emim+][Ac􀀀] (27.5–42.5 %wt.) as a unique plasticizer. According to the results, this ionic liquid is an excellent plasticizer due to the transformation of the crystalline structure of the starch to an amorphous state, the increase in flexibility, and the drop in Tg, as the [Emim+][Ac􀀀] amount increases. These findings show that the properties of these biomaterials could be modified in the function of [Emim+][Ac􀀀] content in the formulations of TPS, depending on their final use, thus becoming a functional alternative to conventional polymers.