Effects of the Addition of Tannic Acid on the Mechanical and Thermal Properties of Biodegradable Polyesters

Abstract

In this study, tannic acid (TA), a naturally derived polyphenol, was employed as an additive to evaluate its effects on the thermal and mechanical properties of two biodegradable polyesters: poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS). TA possesses a large number of phenolic hydroxyl and carbonyl groups and is expected to interact physically with polyester chains, thereby affecting their molecular mobility. According to dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC), Tg increased in TA-containing samples, with DMA showing a Tg shift of approximately 30 °C. In terms of mechanical properties, TA addition led to a significant increase in elongation at break for PBS. The results suggest that TA serves as a functional interaction modifier that can regulate polyester properties through multivalent physical interactions and provides a promising strategy for the functional design of biodegradable polymer materials.