Surface-modified post-crosslinked adsorbents and a process for making the surface modified post-crosslinked adsorbents

A polymeric adsorbent material comprising (a) a substrate of a porous post-crosslinked polymer of at least one monoethylenically unsaturated monomer and a crosslinking agent, wherein at least one monethylenically unsaturated monomer is styrene and the crosslinking agent is divinylbenzene, said polymer being post-crosslinked by the steps of (i) reacting the polymer with a polyfunctional haloalkylating or acylating agent to form a haloalkylated or acylated polymer, (ii) swelling the resulting haloalkylated or acylated polymer with an inert swelling agent to form a swollen, haloalkylated or acylated polymer, and then (iii) maintaining the swollen, haloalkylated or acylated polymer at a temperature and in the presence of a Friedel-Crafts catalyst such that haloalkyl or acyl moieties on the polymer react with an aromatic ring of an adjacent polymer chain to form a bridging moiety, and (b) at least one non-optically active, surface-modifying polymer of an ethylenically unsaturated monomer, said surface-modifying polymer being incorporated and immobilized onto the substrate.