Author(s)

Takahiko Nakaoki^*, Hiroyuki Yamashita

Department of Materials Chemistry, Ryukoku University, Otsu, Japan.

The size and weight fraction of crystals of pure ice or dimethylsulfoxide (DMSO) in poly(vinyl alcohol) (PVA) gel prepared from a mixed solvent of DMSO/water were determined from melting peaks observed by differential scanning calorimetry (DSC). The depression of the melting point with respect to the equilibrium melting point and the melting enthalpy gave the crystal size and weight fraction, respectively. The sizes were in the range of a few nm to tens of nm, depending on the composition ratio of the mixed solvent (DMSO/water) and the polymer concentration. Based on the weight fraction, the critical condition at which the whole solvent became non-freezable was estimated, and it was found to depend on both the PVA concentration and the DMSO/water ratio. When the solvent was pure water, the critical PVA concentration was as high as 86.4 wt%, while for pure DMSO solvent it was 50.1 wt%.

Poly (Vinyl Alcohol), Gel, Size of Solvent Crystals, Non-Freezable Solvent, DMSO, DSC

Nakaoki, T. and Yamashita, H. (2016) Size and Weight Fraction of Solvent Crystals in Poly (Vinyl Alcohol) Gel Prepared from Dimethylsulfoxide/Water Solution. Open Journal of Organic Polymer Materials, 6, 86-97. doi: 10.4236/ojopm.2016.62009.