RHEOLOGICAL AND THERMAL-PROPERTIES OF POLY(VINYL ALCOHOL) ETHYLENE-GLYCOL WATER GELS

Effects of ethylene glycol (EG) on rheological and thermal properties of poly(vinyl alcohol) (PVA) gels were studied by longitudinal vibration measurements and differential scanning calorimetry. Elastic modulus of PVA gels as a function of EG content showed a maximum around 0.35 mol fraction (mf) EG, while the melting temperature and the heat absorbed on forming one mol of junction zones increased monotonously with increasing EG content. It was suggested that junction zones of PVA gels become more heat resistant by the addition of EG, however, the number of junction zones becomes maximum around 0.35 mf EG. The results were compared with those for PVA-dimethyl sulfoxide-water gels reported previously.