THERMOLYSIS AND PHOTOCHEMICAL ACIDOLYSIS OF SELECTED POLYMETHACRYLATES

Thermal behavior and thermolytic deprotection catalyzed by photochemically generated HSbF//6 in the solid state have been investigated for atactic polymethacrylates having benzyl, alpha -methylbenzyl, alpha , alpha -dimethylbenzyl, and tert-butyl ester groups as well as cyclopropyl carbinol esters. It is shown that sensitivity of these polymethacrylates to photochemically induced acidolysis is very much reflected by the thermal deprotection temperatures except for the cyclopropyl carbinol esters, which possess the lowest deprotection temperature in the series but suffer from concomitant rearrangement to a thermally stable primary ester. The thermal rearrangement of the cyclopropyl carbinol ester, is more pronounced in the presence of acids.