Degradation processes in polyolefins with phenolic stabilizers subjected to ionizing or non-ionizing radiation

0583350 - ÚMCH 2025 RIV NL eng J - Článek v odborném periodiku
Šlouf, Miroslav - Gajdošová, Veronika - Šloufová, I. - Lukešová, Miroslava - Michálková, Danuše - Müller, M. T. - Pilař, Jan
Degradation processes in polyolefins with phenolic stabilizers subjected to ionizing or non-ionizing radiation.
Polymer Degradation and Stability. Roč. 222, April (2024), č. článku 110708. ISSN 0141-3910. E-ISSN 1873-2321
Grant CEP: GA MZd(CZ) NU21-06-00084; GA TA ČR(CZ) FW01010564
Institucionální podpora: RVO:61389013
Klíčová slova: high-density polyethylene (HDPE) * cycloolefin copolymer (COC) * natural phenolic stabilizers
Obor OECD: Polymer science
Impakt faktor: 5.9, rok: 2022
Způsob publikování: Omezený přístup
https://www.sciencedirect.com/science/article/pii/S0141391024000521?via%3Dihub

We investigated degradation processes in polymer plaques made of polyolefin (HDPE or UHMWPE or COC) prepared by melt-mixing with or without phenolic stabilizer (natural α-tocopherol or synthetic Irganox®1010) and spin trapping agent (TTBNB, 2,4,6-Tri‑tert-butylnitrosobenzene). The degradation was initiated either by low-energy, non-ionizing radiation (wavelengths corresponding to terrestrial range of solar UV radiation) or high-energy, ionizing radiation (electrons accelerated at 1.5 MeV). The motivation for the study was our recent finding that some phenolic stabilizers exhibited a surprising pro-oxidant activity in polyolefins subjected to non-ionizing radiation. Consequently, we asked if the phenolic stabilizers in polyolefins behave in the same way during long-term, low-energy, non-ionizing UV irradiation and after short-term, high-energy, ionizing e-beam irradiation. All samples were characterized thoroughly by means of electron spin resonance (ESR, the information about radiation-induced radicals), infrared microspectroscopy (IR, the detection of oxidation products and structural changes), instrumented microindentation (MHI, local mechanical properties) and light and electron microscopy (LM and SEM, surface morphology). The results proved that (i) the degradation processes in polyolefins subjected to non-ionizing or ionizing radiation were different, (ii) the phenolic stabilizers exhibited mostly their expected antioxidant activity, while pro-oxidant activity was detected only for specific conditions and/or systems subjected to non-ionizing radiation, and (iii) the selected spin trapping agent, TTBNB, was stable enough to survive standard sample preparation by melt-mixing and catch short-living unstable radicals.
Trvalý link: https://hdl.handle.net/11104/0351895