ABSTRACT To address the global challenges of fossil fuel depletion and plastic pollution, promoting sustainable environmental development, we have explored the use of wheat gluten (WG) as a possible insulating material in electric applications. Inspired by previous work on whey protein foams, where a thermal treatment improved the mechanical integrity, WG was also here heat‐treated at 150°C in air, and films were produced with and without a plasticiser (glycerol, GLY). The overall properties depended on the composition, processing conditions, environment, and whether a heat‐treatment was used or not. At best, films exhibited an electric insulation competitive to fossil‐based plastics (7.2 × 10 14 Ω·m), oil resistance, and a comparatively low moisture uptake. Quite unexpectedly, these films, prepared with glycerol, remained flexible even after 4 weeks at 150°C. These results suggest that thermally treated WG/GLY materials have the potential to be used in e.g. low‐voltage insulation parts in electric motors, achieving a balance between performance and sustainability in automotive applications.
Wang et al. (Sun,) studied this question.