Influência de líquidos iônicos e solventes eutéticos profundos sobre as propriedades fisico-químicas de filmes à base de amido.

Abstract

The development of biopolymers that use starch as a raw material has been growing recently, due to the demand for more sustainable materials, seeking the substitution of synthetic polymers based on non-renewable sources, mainly the ones that come from petroleum sources. Biodegradable films based on natural matrices exhibit promising mechanical and vapor barrier properties and have shown great potential in research aimed at maintaining the quality and improving the useful life of minimally processed fruits and foods. To obtain it, it is necessary to use plasticizers, e.g. water and glycerol. However, the application of glycerol has been challenged due to the strong tendency it has to favor the retrogradation of starch during the storage period. Therefore, Deep Eutectic Solvents (DES) and Ionic Liquids (ILs) have been evaluated as a promising alternative to replace the common additives mentioned before, due to their ability to interact with the polymeric matrix so that retrogradation is minimized. Thus, the main objective of this work is to evaluate the capacity of the [ChCl:CA] eutectic solvent and the ionic liquid [Ch][CA] as plasticizers in the formulation of starch-based biodegradable films. The evaluation of the efficiency of these compounds was carried out through the analysis of their physical-chemical properties, optical properties, and interaction with water, using the plasticized film with glycerol as a standard. The data obtained in this work shows that the two selected plasticizers demonstrated great efficiency for the various parameters studied. The film doped with ChCl:CA and [Ch][CA] showed greater solubility in water and were more efficient in terms of water vapor permeability. Glycerol, despite being a widely used plasticizer, was not efficient at low concentrations, while DES and IL are able to form the film even at concentrations below 1%. In addition, the results obtained with [ChCl:CA] showed better physical-chemical properties when compared to the standard, in which only glycerol was used as an additive. Thus, choline-derived plasticizers are an alternative to the classic means for obtaining biodegradable starch films.