Synthesis and surface activity of poly(maleic diester) surfactants

A series of maleic diester monomers have been prepared by esterification of maleic anhydride with a series of n-alkanols and poly(ethylene glycol) wit h different molecular weights. These monomers were polymerized in acetic an hydride solution in the presence of cumene hydroperoxide as initiator. The synthesized polymers have been characterized by IR and H-1 NMR spectroscopy , and their surface and thermodynamic properties as non-ionic surfactants i s investigated. The surface tension as a function of concentration of the s urfactant in aqueous solutions was measured at 298, 308, 318 and 328K. The surface parameters are calculated. The data reveal that the CMC value of th e polymeric surfactant is lower than that of the monomeric surfactant. It i s also found that the CMC value decreases with increasing temperature and t he number of ethylene oxide units in the surfactant molecule. The thermodyn amic parameters of micellization and adsorption are also determined. The st ructural effectiveness of surface tension is discussed in terms of these pa rameters. (C) 1999 Society of Chemical Industry.