An Investigation of Stable Free Radicals in Polyimides Using EPR Spectroscopy

Autor:	Kenneth J. Bowles, Thomas C. Stringfellow, Jianming Lei, Myong K. Ahn, Michael A. Meador
Rok vydání:	1993
Předmět:	Matrix (chemical analysis) Materials science Nuclear magnetic resonance law Radical Degradation (geology) Oxygen gas Photochemistry Electron paramagnetic resonance Spectral line Polyimide law.invention
Zdroj:	MRS Proceedings. 305
ISSN:	1946-4274 0272-9172
DOI:	10.1557/proc-305-217
Popis:	Polyimide resins are used as matrix materials in fiber reinforced composites. Such composites are lightweight, have relatively high strength, and can be used at temperatures above 300°C. Postcured PMR-15 produces room temperature electron paramagnetic resonance (epr) spectra from stable free radical species formed during the postcuring stages. The variable temperature EPR spectral intensities indicate the presence of at least two free radical species. The thermo-oxidative degradation involves free radicals generated during the postcuring process in the presence of oxygen gas. These and other recent results including ENDOR and HYSCORE work are discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c234be67291ed88fec52e1384c487ec4 https://doi.org/10.1557/proc-305-217 Zobrazit plný text záznamu Full text from SpringerLink