Preparation of highly porous, cross-linked polyHIPE composites for biological applications

Emulsion templating is a simple and effective route for the preparation of macroporous and open-cellular polymers through high internal phase emulsions (HIPEs). HIPEs are defined as concentrated emulsion systems consisting of a high ratio of internal or dispersed phase. The volume fraction (Ø) of the internal phase of a HIPE is usually greater than 0.74 and can reach levels of 0.99. Polymerization of the continuous phase or both phases of HIPEs leads the formation of polymers so-called "polyHIPEs". Because of their unique properties, polyHIPEs have been developed for several applications including filter membranes, ion exchange resins, ultraporous polymer supports in organic synthesis, chromatographic support materials, and tissue engineering applications. However, the real industrial applications have been restricted as a result of poor mechanical strength arised from the porous structure. With this thesis porous functional polymer composites having prepared mechanical strength have been prepared by using emulsion templating method. With this aim, in order to improve the mechanical properties a water soluble and biocompatible polysacharite (pullulan) have been used instead of classical reinforcements. The research has been made in two different stages consisting of the preparation of polyHIPEs in the form of monoliths and microspheres. At the first stage, polyHIPE monoliths have been obtained by polymerizing the continuous phase of glycidyl methacrylate/1,3-butanediol dimethacrylate (GMA/BDDMA) and GMA/BDDMA/pullulan HIPEs. At the second stage polyHIPE microspheres have been obtained by the polymerization of dispersed GMA/BDDMA and GMA/BDDMA/pullulan HIPE droplets in a secondary suspension medium. The morphological, mechanical and thermal properties of the resulting polyHIPEs have been characterised depending on the preparation conditions. Afterwards, in order to determine the usage of polyHIPEs in biological applicatons such as enzyme immobilization and protein prufication, post-functionalisation reactions have been carried out by using reactive amine compunds.