STRUCTURAL CHARACTERISTICS AND SWELLING BEHAVIOR OF POLY(ETHYLENE GLYCOL) DIACRYLATE HYDROGELS

Poly(ethylene glycol)s (PEGs) in the molecular weight range 200-3400 w ere derivatized at both ends with acryloyl chloride. These poly(ethyle ne glycol) diacrylates (PEGDAs) on homopolymerization yield cross-link ed networks whose M(c) values should correspond to the molecular weigh t of the PEGDA macromer. M(c) values calculated according to the Flory -Rehner equation compare very well with the theoretical values for low concentrations of low molecular weight monomers. Those at high concen trations and higher molecular weights are always lower than the expect ed values. Attempts to resolve the equilibrium swelling and elastic co mponents indicate that the phantom model gives a better fit.