Thermal and mechanical characterization of films based on poly(vinyl alcohol) and β‐lactoglobulin blends

Abstract

In this study, we investigated the possibility of creating easy to handle films based on poly(vinyl alcohol) (PVA) and β‐lactoglobulin (βlg) blends using the casting method. Four different variables were studied to obtain these films: different proportions of PVA and βlg, different pHs (10, 7, 5.5, and 2.5), several molecular masses of PVA (130,000, 13,000–23,000, and 2000 g/mol), and the denaturation of βlg. The first objective was to obtain films, and the second was to characterize them by differential scanning calorimetry, thermogravimetric analysis, and mechanical testing. Significant variations in behavior were found, and the variables studied modified the blends in different ways. In particular, better results were achieved when the βlg proportion was less than 30 wt %, and when a pH of 2.5 was used in conjunction with a high molecular mass (130,000 g/mol) of PVA. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41745.