N-Methylammonium salts, N-methy-p- or o-cyanopyridinium, o-chloropyridinium, O-methoxypyridinium, 2,6-dichloropyridinium, 2,6-dimethylpyridinium, 3-bromoquinolinium, 2-phenyl-4-methoxycarbonylquinolinium, 8-nitroquinolinium, benzothiazolium, 2-methylthio-benzothiazolium hexafluoroantimonates were synthesized by the reaction of dimethyisulfate and the corresponding hetero-compounds, followed by anion exchange with KSbF6. The N-methyl-pyridinium salts substituted electron-withdrawing group polymerized at epoxy monomer at the temperature lower than the ones substituted electron donative group. A combination of N-methylammonium salts and peroxides could polymerize epoxy monomer at lower temperature than N-methylammonium salts only. These N-methylammonium salts initiated photo-radical polymerization as well as photo-cationic polymerization. The photo-polymerization was accelerated by the addition of aromatic compounds, 2,2-dimethoxy-2-phenylacetophenone, aromatic ketones as photosensitizers.

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We have synthesized the polyurethane resins as a pressure sensitive adhesive (PSA) and have evaluated its properties. The PSA have both medium peel strength and good removability. We propose that the soft segment of this synthesized polyurethane resin performs as adhesive and hard segment and linkage system works for removability. By increasing the content of hard segments and linkage system, rubber-like elasticity range of dynamic mechanical properties rise, which improves removability. It shows that an increase of cohesive energy works for better removability. And we propose that the fact that it increases surface free energy as a result of increasing content of hard segments is the reason this PSA has both medium adhesion and good removability.

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