Synthesis and Characterization of Cross-Linked Acrylic Acid/POSS Hydrogels: Effects of the POSS Amount and pH Value on Swelling

In this work, series of pH sensitive acrylic acid hydrogels have been prepared by free radical polymerization in the presence of octavinyl polyhedral oligomeric silsesquioxane (OVS) as a crosslinking agent. Different percentage of OVS was used to investigate the effect of cross-linking density on swelling of hydrogels. Dynamic and equilibrium swelling studies of prepared hydrogels were investigated in USP phosphate buffer solutions of pH 3, 7.4 and 8 with constant ionic strength. The highest swelling ratios reached at basic medium (pH 8) for all samples. The swelling ratios of the hydrogels with different amount of crosslinking agent (4, 7 and 10 %) in neutral medium (pH = 7.4) were 44, 89 and 37 respectively.

Keywords:

Hydrogel , Acrylic acid , pH sensitive , Drug delivery , POSS