Study of the Plasticization Effect of 1-Ethyl-3-methylimidazolium Acetate in TPS/PVA Biodegradable Blends Produced by Melt-Mixing

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 T-g, 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.

Automated summary

The behavior of thermoplastic starch (TPS)/polyvinyl alcohol (PVA) films plasticized with the green solvent 1-ethyl-3-methylimidazolium acetate ([Emim(+)][Ac-]) ionic liquid was studied. The addition of [Emim(+)][Ac-] in different concentrations transformed the crystalline structure of starch, increased flexibility, and decreased T-g, making it a potential alternative to conventional polymers.