Abstract

A mixed hydrogel containing poloxamer 407 (P407) and cross-linked polyvinyl alcohol (cPVA) was prepared by varying the ratio of two polymer concentrations to make hydrogel formulations. The hydrogel formulations were determined for molecular interaction, viscoelastic, thermal properties and phase behavior. The results indicated that all hydrogels were clear and semi-solid. The cPVA was obtained from the crosslink between the PVA with borate and the PVA with borate and ascorbate. These molecules interacted to each other by forming the hydrogen bonding between borate ions, ascorbate and polymer chains or formed intermolecular and intramolecular hydrogen bonding. There is no chemical interaction between the molecules of cPVA and P407. The viscoelasticity of hydrogels exhibited sol-gel transition as frequency and temperature sweep. Incorporating cPVA into hydrogel elevated gelling temperature of P407 from 14.05 to 29.7 °C. The thermal properties of hydrogel revealed two melting point, 54–57 °C and 78–81 °C. The crystallization of hydrogel occurred at temperature lower than 40 °C and void spaces were presented at the cooling phase of the thermal study. The P407 has a lamellar structure and is stable even when the cPVA was added. The cPVA can be inserted into the interlamellar spacing of P407. It was concluded that a mixture of P407 and cPVA was suitable for the development of hydrogel.