Abstract

In this work the effect of citric acid concentration on the structure and properties of glycerol-plasticized thermoplastic starch films was systematically investigated. Films containing increasing citric acid contents (10-70% w/w with respect to starch) were prepared and characterized. The combined characterization approach highlighted the coexistence of mobile low-molecular-weight species and of covalent and/or supramolecular interactions, within the thermoplastic starch matrix. The dataset includes the following characterization data: Attenuated Total Reflectance - Fourier Transform Infrared (ATR FTIR) spectroscopy: to confirm the chemical structure of the original samples and of the films after the extraction of non-covalently integrated glycerol and citric acid. Cyclic microtensile measurements: to investigate the partial network formation through cyclic stress-strain measurements and to determine the dissipated energy and recovered deformations. Differential scanning calorimetry (DSC) analysis: to study the glass transition temperature and the amorphous phase of as produced films and of the films after the extraction of non-covalently integrated glycerol and citric acid. Stress-strain measurements: to investigate the mechanical properties of all the films when subjected to monotonic tensile tests. Thermogravimetrical analysis (TGA): to study the thermal stabilities of all the samples. X-ray photoelectron spectroscopy (XPS): to investigate the surface chemistry of original samples and samples after the extraction of non-covalently linked glycerol and citric acid. This comprehensive dataset supports the findings presented in the manuscript and provides detailed insights into the characterization and properties of citric acid modified glycerol-thermoplastic starch films.