148481 20260217205540.0 doi 10.1021/acsapm.4c03030 sideral 141858 ART-2024-141858 eng Paiva, Robert How Carbodiimide Modulates Oligomer Migration and Molar Mass in Recycled Poly(lactic acid): A Study Using UPLC-QTOF-MS^E 2024 Access copy available to the general public Unrestricted The recycling of polymers for direct food contact faces initial challenges due to the loss of molar mass and the generation of Non-Intentionally Added Substances (NIAS), among which oligomers are prominent. In this study, carbodiimide (CDI) was employed as an antihydrolysis agent and chain extender to prevent oligomer formation in the recycling of poly(lactic acid) (PLA). Mechanical recycling was performed on wet and dried PLA with varying concentrations of CDI using corotating intermeshing twin-screw extrusion. CDI contributed to the increase in polymer molar mass and influenced the kinetics of its nonquiescent crystallization. Moisture played a key role in this process, as CDI can react either with water molecules, preventing hydrolytic degradation, or with available sites on the PLA molecule, resulting in increased molar mass and a decrease in the oligomer content. Oligomer migration tests were conducted using three food simulants: ethanol 10%, acetic acid 3%, and ethanol 95%. Ultraperformance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometer was utilized for qualitative and quantitative PLA oligomer analyses. Electronic structure calculations based on the GFN-xTB Hamiltonian were employed for structural optimizations and energies to understand migration and interaction processes in the described systems. Sixteen different PLA oligomers were detected in the food simulant samples. Linear oligomers were identified in all simulants, while cyclic were detected mainly in the 95% ethanol simulant. The antihydrolysis and chain-extending effects of CDI in recycled PLA reduced the total oligomer concentration in both wet and dry samples, improving the physicochemical properties of PLA and ensuring food safety. info:eu-repo/grantAgreement/ES/DGA-FSE/T53-20R info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es 4.8 2024 POLYMER SCIENCE 22 / 94 = 0.234 2024 Q1 T1 MATERIALS SCIENCE, MULTIDISCIPLINARY 148 / 461 = 0.321 2024 Q2 T1 0.981 2024 Organic Chemistry 2024 Q1 Polymers and Plastics 2024 Q1 Process Chemistry and Technology 2024 Q2 6.9 2024 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Bonatti, Sophia H. F. Estremera, Carlos Wrona, Magdalena Universidad de Zaragoza (orcid)0000-0003-2052-3012 Ramos, Vania Martins de Lima Batista, Ana Paula Staffa, Lucas H. Nerín, Cristina Universidad de Zaragoza (orcid)0000-0003-2685-5739 Cruz, Sandra A. 2009 750 Universidad de Zaragoza Dpto. Química Analítica Área Química Analítica 6, 24 (2024), 15230-15241 ACS appl. polymer. mater. ACS applied polymer materials 2637-6105 5731695 http://zaguan.unizar.es/record/148481/files/texto_completo.pdf Versión publicada 3309377 http://zaguan.unizar.es/record/148481/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:148481 articulos driver 2026-02-17-20:36:02 ARTICLE