  Citation: Popa, M.S.; Radu, E.R.; Panaitescu, D.M.; Gabor, A.R.; Nicolae, C.A.; Raduly, M.F.; Frone, A.N. The Potential of Biopolyesters as Plasticizers for Polylactide. Chem. Proc. 2022, 7, 14. https://doi.org/ 10.3390/chemproc2022007014 Academic Editors: Mihaela Doni, Florin Oancea, Zina Vuluga and Radu ClaudiuFierăscu Published: 28 February 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Abstract The Potential of Biopolyesters as Plasticizers for Polylactide † Marius Stelian Popa, Elena Ruxandra Radu, Denis Mihaela Panaitescu , Augusta Raluca Gabor, Cristian Andi Nicolae, Monica Florentina Raduly and Adriana Nicoleta Frone * Polymer Department, National Institute for Research & Development in Chemistry and Petrochemistry—ICECHIM, 011061 Bucharest, Romania; popamarius7777@gmail.com (M.S.P.); radu.elena.ruxandra@gmail.com (E.R.R.); panaitescu@icechim.ro (D.M.P.); raluca.gabor@icechim.ro (A.R.G.); cristian.nicolae@icechim.ro (C.A.N.); monica.raduly@icechim.ro (M.F.R.) * Correspondence: adriana.frone@icechim.ro † Presented at the 17th International Symposium “Priorities of Chemistry for a Sustainable Development” PRIOCHEM, Bucharest, Romania, 27–29 October 2021. Keywords: polyesters; poly(lactic acid); blends; ductility It is estimated that fossil fuel resources will dwindle by the end of 2050 if the current utilization rate persists [1]. Consequently, the scientific community has searched for new polymer materials that can decrease the consumption of fossil plastics, with focus on biodegradable bioplastics. Poly(lactic acid) (PLA) is the frontrunner of bioplastics due to its excellent mechanical properties, compostability, bio-based nature and a cost comparable to conventional polyolefins [2,3]. Still, its inherent brittleness often hinders its utilization where ductility of the material is required. Therefore, in this study, we focus on solving this issue by synthesizing bio-based polyesters for tuning PLA’s ductility. These materials were obtained from 1,4-butanediol (B) and sebacic acid (S) in various molar ratios, using titanium (IV) butoxide (TBT) as a catalyst. The sebacic acid (S) (purity 99%), 1,4-butanediol (purity 99%) (B) and titanium (IV) butoxide (TBT)were used as received without further purifications. The PLA was blended with the obtained bio-based polyesters via melt mixing. The obtained polyesters and PLA-based blends were characterized by FT-IR, TGA, DSC, DMA, water contact angle and tensile properties. The introduction of the bio-based polyesters in the PLA matrix led to a monotonous decrease of the tensile strength, along with a considerable increase of elongation at break. The proposed bio-based polyesters exhibited a good plasticizing effect on PLA, thus broadening its applications. Author Contributions: Methodology, Writing original draft, M.S.P.; Formal analysis, E.R.R., D.M.P., A.R.G., C.A.N., M.F.R.; Conceptualization, Funding, Validation, A.N.F. All authors have read and agreed to the published version of the manuscript. Funding: This work was supported by a grant fromthe Ministry of Research, Innovation and Digiti- zation, CNCS/CCCDI—UEFISCDI, project number 67TE/2020, within PNCDI III. Institutional Review Board Statement: Not applicable. Informed Consent Statement: Not applicable. Data Availability Statement: Not applicable. Conflicts of Interest: The authors declare no conflict of interest. Chem. Proc. 2022, 7, 14. https://doi.org/10.3390/chemproc2022007014 https://www.mdpi.com/journal/chemproc