The Photogeneration of Polymeric Amines: Synthesis and Photocrosslinking of Copolymers Containing Photoactive Carbamate Pendant Groups

Two families of copolymers containing 4-(2-NITROBENZYLOXY)-CARBAMOYL- styrene as the photoactive component, with styrene or methyl methacrylate as the other component are described. The polymers are prepared by chemical modification of copolymers of 4-amino-styrene with styrene and methyl methacrylate, respectively, using 2-nitrobenzyl chloroformate. The photoactive carbamate groups of both copoly can be removed by irradiation with UV light below 320nm. Quantum yield measurements and comparisons with small molecule model compounds confirm that attachment to the polymer has no effect on the photolability of the 2-nitrobenzyl carbamoyl protecting group. Quantum yield values near 0.10 also compare favorably with those obtained for related small molecules. The photoactive polymers have been tested successfully in the UV induced crosslinking of formulations containing epoxy groups.