Swelling, Thermal and Mechanical Properties of Poly(vinyl alcohol)/Sodium Alginate Hydrogels Synthesized by Electron Beam Irradiation

Abstract

Highly hydrophilic hydrogels composed of various contents of poly(vinyl alcohol) (PVA) and sodium alginate (AG) were produced by exposure to electron beam irradiation. The hydrogels were characterized by IR spectroscopy, mechanical testing and thermogravimetric analysis (TGA). The kinetic parameters of the thermal decomposition were determined by the Kissinger method (different heating rates). In addition, the swelling behavior in different temperatures and pH values was studied. The IR spectroscopic analysis indicates the formation of interpenetrating polymer networks and the presence of hydrogen bonding. The thermal study showed that the PVA/AG hydrogels, over the studied compositions, possess higher thermal stability than pure PVA hydrogel. The kinetic studies of swelling in water showed that pure PVA and PVA/AG hydrogels reaches equilibrium after 4 h. However, PVA/SAG hydrogels show swelling in water greater than pure PVA hydrogel. It was found that the swelling of PVA/AG hydrogels increases greatly within the temperature range 10–25°C, and the pH range 5–7 depending on composition. This behavior was clear in the case of PVA/AG composed of higher contents of AG.