Characterization of hydrogels formed from acrylate modified poly(vinyl alcohol) macromers

Poly(vinyl alcohol) was modified with pendent acrylate groups to form a mac romer that was crosslinked via photopolymerization. Polymerization behavior was studied for several initial macromer concentrations using DSC and Near -IR spectroscopy. Under mild photoinitiating conditions (e.g. 0.05 wt% init iator and less than 20 mW/cm(2) of 365 nm light), the hydrogels polymerized to 100% conversion in less than 5 min. To characterize the network structu re, the hydrogels formed from the acrylated poly(vinyl alcohol) macromer we re compared to gels that were chemically crosslinked with glutaraldehyde an d gels that were physically crosslinked by semi-crystalline regions introdu ced through freeze-thaw cycles. The equilibrium swelling ratio and compress ive modulus were characterized for all of the resulting PVA hydrogels, and related to the network structure (i.e. <(M-c)over bar>) through a modified Flory-Rehner equation and rubber elasticity theory. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.