Polyvinyl alcohol cross-linked macroporous polymeric hydrogels: Structure formation and regularity investigation

A series of novel polyvinyl alcohol (PVA) hydrogels were synthesized by cross-linking of acrylate-modified PVA in aqueous solutions. Hydrogels were prepared at a temperature range -7.5 to -25 degrees C, macromer concentration 4-12 wt.%, and initiator concentration 0.4 to 1.6 mg/ml. The swelling behavior of polymeric hydrogels in aqueous media with different pH and ionic strength values was investigated. It was shown that they possess a high level of water absorption. The influence of different factors (porosity, pore size, and pore size distribution) and reaction conditions on the hydrogel structure was studied. The interior morphology of the hydrogel networks exhibits a complicated structure filled by fibrillar, lamellar and dendritic formations consisting of cross-linked polymer. The dispersed pores which are randomly distributed can be observed inside these formations and between them. (C) 2010 Elsevier B.V. All rights reserved.