Lomakin, S.; Mikheev, Y.; Usachev, S.; Rogovina, S.; Zhorina, L.; Perepelitsina, E.; Levina, I.; Kuznetsova, O.; Shilkina, N.; Iordanskii, A.; Berlin, A. Evaluation and Modeling of Polylactide Photodegradation under Ultraviolet Irradiation: Bio-Based Polyester Photolysis Mechanism. Polymers2024, 16, 985.
Lomakin, S.; Mikheev, Y.; Usachev, S.; Rogovina, S.; Zhorina, L.; Perepelitsina, E.; Levina, I.; Kuznetsova, O.; Shilkina, N.; Iordanskii, A.; Berlin, A. Evaluation and Modeling of Polylactide Photodegradation under Ultraviolet Irradiation: Bio-Based Polyester Photolysis Mechanism. Polymers 2024, 16, 985.
Lomakin, S.; Mikheev, Y.; Usachev, S.; Rogovina, S.; Zhorina, L.; Perepelitsina, E.; Levina, I.; Kuznetsova, O.; Shilkina, N.; Iordanskii, A.; Berlin, A. Evaluation and Modeling of Polylactide Photodegradation under Ultraviolet Irradiation: Bio-Based Polyester Photolysis Mechanism. Polymers2024, 16, 985.
Lomakin, S.; Mikheev, Y.; Usachev, S.; Rogovina, S.; Zhorina, L.; Perepelitsina, E.; Levina, I.; Kuznetsova, O.; Shilkina, N.; Iordanskii, A.; Berlin, A. Evaluation and Modeling of Polylactide Photodegradation under Ultraviolet Irradiation: Bio-Based Polyester Photolysis Mechanism. Polymers 2024, 16, 985.
Abstract
In our study we investigated the accelerated aging process of PLA under 253.7 nm UV-C irradiation with the use of GPC, NMR, FTIR, DSC methods and formal kinetic analysis. The results of GPC and DSC indicated a significant degree of destructive changes in PLA macromol-ecules, while spectroscopic methods NMR and FTIR showed maintenance of PLA main structural elements even after a long time of UV exposure. In addition to that, the GPC method displayed the formation of a high-molecular fraction starting from 24 hours of irradiation, and an increase in its content after 144 hours of experiment. It has been showed for the first time that a distinctive feature of prolonged UV exposure is the occurrence of intra- and intermolecular radical recom-bination reactions, leading to the formation of a high-molecular fraction of PLA decomposition products. This causes the observed slowdown of the photolysis process. It was concluded that photolysis of PLA is a complex of physicochemical processes, the mechanism of which depends on morphological changes in a solid phase of the polymer under UV radiation.
Keywords
polylactide; Differential Scanning Calorimetry; Gel Permeation Chromatography; IR Spectroscopy; NMR Spectroscopy; kinetics; UV Radiation
Subject
Chemistry and Materials Science, Biomaterials
Copyright:
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