The Study of the Swelling Degree of the PVA Hydrogel with varying concentrations of PVA

Abstract

Hydrogel is composed of a three-dimensional network of hydrophilic polymers and can swell when placed in an aqueous media. Polyvinyl alcohol (PVA) is a common polymer used to produce hydrogels because it has biocompatibility, non-toxicity, chemical stability, low cost, and excellent mechanical strength. In this study, the PVA solutions were prepared with concentrations of 6%, 8%, 10%, and 12% in distilled water. The precursor solutions underwent a freeze-thaw cycle with a freezing temperature of -25 °C for 20 hours and a thawing temperature of 37 °C for 4 hours and carried out for 6 cycles. The swelling degree and the gel fraction of the hydrogel were then determined. From the swelling degree results, the increase of the PVA concentration in the precursor solutions reduced the swelling degree of the hydrogel. Based on the gel fraction test, it was revealed that all PVA concentrations have approximately the same value of gel fraction at 97%. Additionally, the viscosity and the density were also measured. Both showed an increasing trend with the addition of PVA concentration, where the viscosity values from the smallest to highest concentrations were 12.4944, 34.1737, 93.8491, and 216.2979 cP while the density values were 0.9865, 0.9871, 0.9878, and 0.9885 gram.cm-3.