SITE-SPECIFIC PHOTOCHEMICAL-REACTION OF PMMA AND RELATED POLYMERS BY INNER-SHELL ELECTRON-EXCITATION

The photoion desorption by inner shell electron excitation from solid films of poly(methyl methacrylate), poly(methyl acrylate) and poly(met hacrylic acid) was studied. The assignment of the features observed in the absorption spectrum of PMMA was elucidated by a systematic compar ison of the H+ yield spectra of the three polymers. Detailed informati on about the specific excitations that promote the desorption of CH3ions was obtained both in the carbon and oxygen K-edge regions. It was observed that most of the PMMA CH3+ ions are desorbed by the fragment ation at the side chain.