Microporous thermally sensitive hydrogels based on hydroxypropyl cellulose crosslinked with poly-ethyleneglicol diglycidyl ether

New microporous thermally sensitive hydrogels were prepared by crosslinking hydroxypropylcellulose (HPC) with poly-ethyleglicol diglycidyl ether. The crosslinking reaction was carried out in heterogeneous liquid crystalline phase. Phase separation was obtained at room temperature by using the mixed solvent water/dimethylsulfoxide (DMSO). A study of phase equilibrium for the ternary system HPC/water/DMSO is reported. Hydrogels obtained from heterogeneous conditions show a porous structure with interconnected channels characterized by high solvent adsorption rate, while gels obtained from homogeneous solutions show a compact structure. The hydrogels have thermally sensitive behaviour, swelling at low temperature and contracting at high temperature. A thermal cycle corresponding to a reversible process of solvent absorption and deabsorpion is illustrated.