Preparation and functionalization of (vinyl)polystyrene polyHIPE® -: Short routes to binding functional groups through a dimethylene spacer

This paper describes the preparation and post-functionalization of an emulsion-derived polymeric foam, called polyHIPE(R), bearing pendant vinyl functionalities. The large pores and large channels of polyHIPE allow liquids and solvents to be driven through the molded monolith at very low pressure. In the presence of a free-radical initiator, compounds such as HBr and thiols underwent an anti-Markovnikov addition to the residual vinyl groups. Other reactions such as hydroboration with BH3 followed by hydrolysis with H2O2 have also been investigated. In this paper, a comparison between two ways of functionalization has been made: a 'batch' method, corresponding to diffusion of reactants through the pores of small cubes of polymers, and a 'continuous flow' method, forcing reactants to flow through the interconnected porous structure by applied low pressure. (C) 2000 Elsevier Science B.V. All rights reserved.