Synthesis and properties of hydrophilic networks based on poly(ethylene glycol) and β-cyclodextrin

New hydrophilic networks combining poly(ethylene glycol) (PEG) and beta-cyclodextrin (beta-CD) have been prepared. Both components are linked by reacting PEG chains previously endcapped with isocyanate groups and P-CD, forming urethane links. Networks of molar compositions ( beta-CD/REG) ranging from 1/4 to 1/14, and with four different molar masses (400, 600, 900, and 1350 g center dot mol(-1)) of the end-capped PEG precursor have been synthesized. The networks have good thermal stability and low glass transition temperatures. Crystallinity has only been detected for the two higher molar mass PEG precursors. The swelling properties of these hydrogels depend on the chain lengths of the PEG precursor and also on the temperatures.