A novel approach to inducing aqueous base solubility in substituted styrene-sulfone polymers

This paper describes the synthesis of a new terpolymer, poly[(tert-butoxycarbonyloxy) styrene acetoxystyrene sulfone], and provides spectroscopic evidence for the chemical reactions this polymer is capable of undergoing. The (tert-butoxycarbonyloxy)styrene undergoes acidolysis of the tert-butoxycarbonyl moiety in the solid state in the presence of a strong acid. If this acid is generated by exposure to UV light, this reaction can form the basis for imaging this polymer. The acetoxy group can be cleaved from the acetoxystyrene monomer in aqueous base solution only when sulfone is incorporated into the copolymer in the appropriate amounts. After cleavage by base the resulting polymer is soluble in the base solution only if the tert-butoxycarbonyl group has been removed by acid. The polymer has been designed in a novel manner such that each monomer of the copolymer fulfills a different function. IR and NMR studies which emphasize and explain the role of sulfone in facilitating acetoxy hydrolysis are presented.