Degradation of Poly(methyl methacrylate)
1991; American Chemical Society; Linguagem: Inglês
10.1021/bk-1991-0475.ch011
ISSN1947-5918
Autores Tópico(s)Advancements in Photolithography Techniques
ResumoThe chemical changes in PMMA films caused by irradiation with deep UV, x-ray, electron, and proton beams were studied by gel permeation chromatography, FT-IR, UV, and NMR spectroscopy. Quantitative analyses of spectral changes demonstrated a 1:1 correspondence between the disappearance of ester groups and the generation of double bonds in the polymer chain by all types of radiation. The ratio of main chain scission to changes in the number of ester groups and the generation of double bonds for deep UV was very close to the quantum yield of main chain scission of PMMA as reported in the literature. High energy radiation was about ten times more efficient than deep UV in causing main chain scission with removal of fewer ester groups. Four different types of unsaturated bonds were identified in NMR spectra of degraded PMMA films. In additon, conjugated unsaturated bonds were observed in UV-irradiated film at high doses. Polymer stereochemistry and state (solution or solid) exert influence on the course of the degradation process.
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