Thermosensitive lactitol-based polyether polyol (LPEP) hydrogels

A series of new thermosensitive polymer hydrogels were prepared by reacting acylated poly(ethylene glycol) bis(carboxymethyl) ether (PEGBCOCl) with lactitol-based polyether polyols (LPEP). The polyether polyols were generated from propoxylation of lactitol and have molecular weights ranging from 1337 to 4055 g/mol. The hydrogels absorb water up to 1000% of their dry weight and expel free water at temperatures at and above 30°C. The wide ranging swelling behavior and excellent thermosensitivity depend closely on the degree of crosslinking and the propylene oxide lengths in the polyols. Differential scanning calorimetry of the hydrogels showed two endotherms associated with the phase transitions of PO and EO segments in the hydrogel structures. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 979–984, 1998