Tailored Plasticization of Bio- and Fossil-Based Polymers Using a Versatile Bioplasticizer Derived from Phenylacetic Acid and Glycerol

Abstract

For accelerating the shift from fossil-derived plastics toward biopolymers, there is an urgent need to develop efficient and versatile biobased plasticizers to improve biopolymer performance without compromising biodegradability and/or safety. This study explores the versatility of the emerging triphenylacetic glyceroate (TPAG) bioplasticizer by incorporating it into a range of biobased and conventional polymers. An increasing content of TPAG, from 5 to 20 parts per hundred of resin (phr), has been compounded with polyhydroxybutyrate (PHB), polyhydroxybutyrate-co-valerate (PHBV), polyvinyl chloride (PVC), and polybutylene succinate (PBS), which present complicated processability and/or limited mechanical properties as bare polymers. Differential scanning calorimetry reveals a clear reduction in glass-transition temperatures (Tg) for PHB, PHBV, and PVC, with the most significant drop observed for PVC (ΔTg = −25 °C at 20 phr TPAG), confirming the significant plasticizing efficiency of TPAG. A melting temperature decrease is also noted for PHB and PBS, with PHB exhibiting β-crystalline phase formation at high TPAG contents, which is attributed to enhanced chain mobility. Mechanical tests demonstrate that only 10 phr TPAG reduces Young’s modulus across all polymers, importantly enhancing their flexibility. Furthermore, 20 phr of TPAG increases the elongation at break of PVC and PHBV up to 349% and 22%, respectively. Volatility and migration studies demonstrate minimal plasticizer loss with values remaining well below safety limits. Moreover, TPAG addition also tailors both water contact angle and UV-blocking activity of the tested polymers, clearly indicating the versatility and multifunctionality of TPAG as a potentially suitable additive for consumer-facing applications.