Journal of Polymer Science Part A Polymer Chemistry · 1990 · 59 citations · 17 references
Natural SciencesChemistryPolymer ChemistryPolymer MaterialsSpectroscopyPolymer AnalysisPolymer CharacterizationPolymer DegradationPolymer Physical ChemistryPolymer PhysicsRadical ReactionsDegradationPolymer Degradation Under RadiationPolymer Radiation DamagePolymethyl MethacrylateRadiation Chemistry Of PolymersRadiation-induced DegradationRadical MechanismsRadical Species
Abstract The role of radical species in the degradation of poly(methyl methacrylate) (PMMA) induced by γ‐irradiation has been studied by means of electron spin resonance and electron spin echo spectroscopy. The major radical species generated initially at 77 K are assigned to main chain CH and side chain COOCH 2 radicals, and COOCH anion radical. Only the COOCH 2 radical converts to the scission‐type CH 2 C(CH 3 )COOCH 3 radical on warming the sample of >180 K. A part of the CH radical disappears on warming the sample of >265 K. It is concluded that the scission of PMMA main chain occurs by the intramolecular process from the COOCH 2 radical as the precursor state.
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