Hydrogels based on responsive segmented polyurethanes

Abstract

The present project aims the development of chemically cross-linked hydrogels based on segmented polyurethanes copolymers which are stimuli responsive to pH and have controlled properties like the hydrophilic/hydrophobic balance. The polyurethanes will be synthesized from biocompatible commercial polyols like poly(ethylene glycol) (PEG), polycaprolactone dyol (PCL-dyol) and three chain coupling agents: The crosslinking agent, glycerol, the "diluent" agent, ethylene glycol and the "responsive" agent, the 2,2-bis(hydroxymethyl) propionic acid (DMPA). The hydrogels will have constant crosslinking density, while the molar ratio of the diluent and responsive agent will be varied. The hydrophilic/hydrophobic balance will be adjusted by the molar ratio of PEG and PCL-dyol. So, a wide variety of materials of different mechanical and physico-chemistry properties and unpublished in the literature can be produced. The project proposes beside the synthesis, the structural, thermical and mechanical characterization of the synthesized hydrogels and the determination of the swelling capacity in function of the pH of aqueous solutions, by example. The study of pH responsive polymeric hydrogels is of interest to science and technology, due the wide variety of applications, like the biomedical, the development of sensors and drug delivery systems, etc. (AU)