The present invention includes a composition having a co-continuous interconnecting channel morphology. These co-continuous interconnecting channels are predominately occupied with a polymer and particles that control the percolation through the composition. The particles are composed of a material such as an absorbing agent, releasing agent and/or activation agent. The polymer composition may be used to form a desired shaped article such as plug type inserts and liners for closed containers, or it may be formed into a film, sheet, bead or pellet.