Further Step in the Transition from Conventional Plasticizers to Versatile Bioplasticizers Obtained by the Valorization of Levulinic Acid and Glycerol

Luca Lenzi; Micaela Degli Esposti; Simona Braccini; Chiara Siracusa; Felice Quartinello; Georg M Guebitz; Dario Puppi; Davide Morselli; Paola Fabbri

doi:10.1021/acssuschemeng.3c01536

Further Step in the Transition from Conventional Plasticizers to Versatile Bioplasticizers Obtained by the Valorization of Levulinic Acid and Glycerol

ACS Sustain Chem Eng. 2023 Jun 13;11(25):9455-9469. doi: 10.1021/acssuschemeng.3c01536. eCollection 2023 Jun 26.

Authors

Luca Lenzi^{1

2}, Micaela Degli Esposti^{1

2}, Simona Braccini^{2

3}, Chiara Siracusa⁴, Felice Quartinello⁴, Georg M Guebitz⁴, Dario Puppi^{2

3}, Davide Morselli^{1

2}, Paola Fabbri^{1

2}

Affiliations

¹ Department of Civil, Chemical, Environmental, and Materials Engineering (DICAM), Università di Bologna, Via U. Terracini 28, 40131 Bologna, Italy.
² National Interuniversity Consortium of Materials Science and Technology (INSTM), Via G. Giusti 9, 50121 Firenze, Italy.
³ BIOLab Research Group, Department of Chemistry and Industrial Chemistry, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.
⁴ Institute of Environmental Biotechnology University of Natural Resources and Life Sciences Vienna, Department of Agrobiotechnology, IFA-Tulln, Konrad-Lorenz-Strasse 20, 3430 Tulln an der Donau, Austria.

Abstract

In the last two decades, the use of phthalates has been restricted worldwide due to their well-known toxicity. Nonetheless, phthalates are still widely used for their versatility, high plasticization effect, low cost, and lack of valuable alternatives. This study presents the fully bio-based and versatile glycerol trilevulinate plasticizer (GT) that was obtained by the valorization of glycerol and levulinic acid. The mild-conditions and solvent-free esterification used to synthesize GT was optimized by investigating the product by Fourier transform infrared and NMR spectroscopy. An increasing content of GT, from 10 to 40 parts by weight per hundred parts of resin (phr), was tested with poly(vinyl chloride), poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(lactic acid), and poly(caprolactone), which typically present complicated processability and/or mechanical properties. GT produced a significant plasticization effect on both amorphous and semicrystalline polymers, reducing their glass-transition temperature and stiffness, as observed by differential scanning calorimetry measurements and tensile tests. Remarkably, GT also decreased both the melting temperature and crystallinity degree of semicrystalline polymers. Furthermore, GT underwent enzyme-mediated hydrolysis to its initial constituents, envisioning a promising prospective for environmental safety and upcycling. Furthermore, 50% inhibitory concentration (IC₅₀) tests, using mouse embryo fibroblasts, proved that GT is an unharmful alternative plasticizer, which makes it potentially applicable in the biomedical field.