Preparation of highly interconnected hydrophilic polymers from emulsion templates with improved mechanical properties

Highly interconnected hydrophilic polymers were prepared through the polymerisation of (paraffin-oil)-in-water emulsion templates using internal phases below 74 vol%. These were stabilised by Tween 85 and contained acrylamide and N,N'-methylene bisacrylamide, as monomers, in the continuous water phase. The emulsification energy was increased, resulting in increased contact between emulsion droplets, allowing open cellular and highly interconnected structures to be achieved. This was coupled with a reduction in the internal phase volume allowing the obtainment of highly interconnected materials with excellent mechanical properties under compression, producing a Young's modulus of 490 +/- 90 MPa for a material with 36 +/- 3% porosity. It was also found that the morphology of these materials could be altered through variations in the internal phase volume, the surfactant level and the emulsification energy. These porous polymers also possessed quite different behaviours in different solvent environments suggesting applications in controlled release or as rigid absorbents.