REVERSIBLE THERMAL GELATION IN POLYMER SURFACTANT SYSTEMS - CONTROL OF THE GELATION TEMPERATURE

The theological properties of association between a hydrophobically mo dified derivative of poly(sodium acrylate) and a series of nonionic su rfactants of oligoethylene glycol alkyl ether type have been studied. The theological properties of these systems are strongly dependent on the nature of the surfactant aggregate. A sharp increase in viscosity and gelation is observed for some systems when increasing the temperat ure. The temperature of this thermal gelation can be correlated with t he transition from micelles to bilayers observed in the binary water/s urfactant system. By using mixtures of nonionic surfactants and varing the mixing ratio, it is possible to adjust the thermal gelation tempe rature over a wide temperature range. The mechanism of thermal gelatio n is discussed.