Targeted development of hydrophilic porous polysulfonamide gels with catalytic activity

Abstract

We report the use of a template and functional monomers in the synthesis of three novel polysulfonamide gels with new architectures and functional groups. These mesoporous polysulfonamide gels were prepared by the condensation polymerization of benzene-1,3-disulfonyl chloride (as the main precursor), linear monomers, and cross-linkers (as variable precursors) in the presence of a silica template by a combination of sol-gel chemistry and the nanocasting technique. In this synthesis pathway, in situ polymerization onto the template surface led to the construction of a silica/polymer nanocomposite. Next, after removal of the template, the nanocomposite gels were transformed into mesoporous polysulfonamide nanospheres. After the physicochemical identification of the synthesized materials, functionalized polysulfonamides were used as reusable novel catalysts with high efficiency for the Strecker reaction under mild conditions. These polymers have Brønsted/Lewis acid active sites, a mesoporous structure, and hydrogen bonding. Moreover, since these polymers are hydrogels that can absorb water, they can promote the Strecker reaction through chemical absorption of the generated water as a driving force. Overall, this article describes a novel synthesis procedure and application of porous polysulfonamide gels.