Heterogeneity of accelerated photooxidation in stabilized bulk commodity polymers studied by X-band ESRI

0495543 - ÚMCH 2019 RIV DE eng J - Journal Article
Pilař, Jan
Heterogeneity of accelerated photooxidation in stabilized bulk commodity polymers studied by X-band ESRI.
Applied Magnetic Resonance. Roč. 49, č. 11 (2018), s. 1217-1234. ISSN 0937-9347. E-ISSN 1613-7507
R&D Projects: GA MŠMT(CZ) LM2015064
Institutional support: RVO:61389013
Keywords : electron spin resonance imaging * polymer photodegradation * hindered amine stabilizers
OECD category: Polymer science
Impact factor: 0.780, year: 2018

Heterogeneity of photooxidation processes in plaques made of commodity polymers, high-density polyethylene, and cyclic olefin copolymer poly(ethylene-co-norbornene) (Topas® 8007) stabilized with various hindered amine stabilizers. Some of them in combination with UV stabilizers exposed to accelerated weathering were studied using electron spin resonance imaging (ESRI) and three independent microscopic-scale methods: scanning electron microscopy, infrared microscopy, and microhardness testing. Concentration profiles of nitroxides mapping photooxidation process inside polymer plaques along the direction of incident radiation (perpendicular to the irradiated surface of the plaques) were determined by ESRI technique in dependence on the duration of the accelerated photooxidation. ESRI data were complemented with profiles of oxidation products, crystallinity, and microhardness measured inside the plaques along the same direction. Selection of stabilizers in the study was completed with α-tocopherol that is considered as the most active component of excellent processing stabilizer vitamin E.
Permanent Link: http://hdl.handle.net/11104/0289225