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

TL;DR

This paper introduces a new bioplasticizer that improves the performance of various biobased and conventional polymers while maintaining safety and biodegradability.

Contribution

The study demonstrates the versatility of triphenylacetic glyceroate (TPAG) as a bioplasticizer across multiple polymer types.

Findings

TPAG significantly reduces glass-transition temperatures in PHB, PHBV, and PVC polymers.

TPAG increases elongation at break in PVC and PHBV by up to 349% and 22%, respectively.

TPAG shows minimal volatility and migration, meeting safety standards.

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 (T
g) for PHB, PHBV, and PVC, with the most significant
drop observed for PVC (ΔT
g = −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.

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