Polar, monodisperse, reactive beads from functionalized methacrylate monomers by staged templated suspension polymerization

Porous monodisperse poly(methacrylic acid-co-ethylene dimethacrylate) and poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) beads, which can be used as a platform for the production of separation media, polymeric reagents, and supports, have been prepared using the staged templated suspension polymerization process. Since the direct polymerization of methacrylic acid, which would lead to beads bearing carboxyl groups in a single step, is not compatible with the preparation technique, poly(tert-butyl methacrylate-co-ethylene dimethacrylate) beads were prepared and then selectively deprotected. In contrast, beads containing aliphatic hydroxyl groups can be prepared directly despite the high solubility of 2-hydroxyethyl methacrylate in water. The degree of functionalization and porous properties of the beads are largely controlled by the monomer composition in the polymerization mixture. One application for the functionalized beads is the preparation of very selective chiral separation media for HPLC of enantiomers.