Photodegradation of poly(methyl methacrylate) studied by ESR and viscosity measurements

Determination of the photo-degradation level of high impact polystyrene (HIPS) using pyrolysis–gas chromatography–mass spectrometry

“…At times, chain scissions are produced [4]. On other occasions, cross-linking reactions can be observed [5].…”

Electron spin resonance studies of poly(methyl methacrylate) irrdiated with monochromatic light

“…When the irradiations were carried out with the 300 nm light, such small radicals could not be detected. Only a weak nine-line spectrum (11) produced by reaction (4) Furthermore, no radical species was found by irradiating PMMA samples with the light of wavelength longer than 320 nm. The main-chain scission of PMMA is considered to begin from radicals (I) and (11) according to the following scheme3:…”

Thermal and photochemical stability of poly(methyl methacrylate) and its blends with poly(vinyl acetate)

“…These results suggest that photochemical transformations in PMMA and PVAc samples occur with greater efficiency than in their blends. This especially concerns those processes which may decrease the thermal stability of polymers: polymer degradation with bond scission in the main chain (reactions 1, 2 and 10) [28][29][30][31][32][33], and the formation of radicals and macroradicals, which causes changes in the structure and chemical composition of polymer macromolecules (reactions 3-9) [34--36]. …”