Product analyses and crosslink mechanism of plasma‐polymerized methyl methacrylate

Plasma‐polymerized methyl methacrylate (PPMMA) film was produced by a radio‐frequency glow discharge of methyl methacrylate (MMA) gas with argon. PPMMA deposited under a plasma of mild energy was separated into a soluble fraction (sol‐PPMMA) and an insoluble matrix (insol‐PPMMA), which is highly crosslinked, by solvent‐extraction and filtration. The chemical structure of the sol‐PPMMA was determined by pyrolysis/gas chromatography, IR spectroscopy, 1H‐NMR, 13C‐NMR, and elemental analysis techniques. On the other hand, the structure of the insol‐PPMMA was examined with IR spectroscopy, 13C‐NMR with CP/MAS method, and elemental analysis. The crosslinking mechanism in the plasma polymerization of MMA is discussed on the basis of product analyses of the sol‐PPMMA and the insol‐PPMMA.