CONTROLLABLE SPECIFIC INTERACTIONS AND MISCIBILITY IN POLYMER BLENDS .4. EFFECT OF HYDROGEN-BONDING DENSITY IN INTERPENETRATING POLYMER NETWORKS

Sequential interpenetrating polymer networks (IPNs) composed of poly(b utyl acrylate) as the first network and modified polystyrene containin g proton-donor hydroxyl groups [PS(OH)] as the second network are stud ied by d.s.c., transmission electron microscopy and dynamic mechanical analysis. The apparent miscibility between the components increases c onsiderably as the hydroxyl content in PS(OH) increases. However, diff ering from the corresponding blends of the linear polymers, for which similar to 2 mol% hydroxyl introduced into PS(OH) leads to complete mi scibility, the IPNs always show two-phase structures even when the hyd roxyl content in PS(OH) is as high as 30 mol%.