Control of cellulose-supported hydrogel microstructures by three-dimensional graft polymerization of glycol methacrylates

This article describes a method for controlled surface coating of cellulose fibers with micro-size hydrogel particles. The addition of ethyleneglycol dimethacrylate (EDMA) to the diethylene glycol methacrylate (DEGMA) monomer mixture used for grafting resulted in a dramatic enhancement of the grafti ng amount onto ozone-activated fibers and subsequent formation of particles on the fiber surfaces, as observed with AFM and SEM. The enhancement of th e amount of grafting was explained by an initiation of the pendent double b onds and autoacceleration of graft polymerization as indicated by different ial scanning calorimetry (DSC). Such 3-dimensional growth had a maximum at 4% of crosslinker and was significantly reduced when longer crosslinkers we re used. This was explained by a cyclization reaction of the pendant double bonds. The surface structures were controlled by selecting the graft polym erization time. (C) 1999 Elsevier Science Ltd. All rights reserved.