Abstract
A series of nonionic surfactants containing different chains of polyethylene oxide monomethyl ether [-O(CH(2)CH(2)O)(x)CH(3), x = 7, 12, 16, 44 and 112] based on castor oil were synthesized. Their structures were confirmed using FTIR, (1)H-NMR and (13)C-NMR spectra. Structural effects of the synthesized surfactants on surface tension (gamma), critical micelle concentration (cmc) and hydrophile lipophile balance (HLB) were investigated. The effect of structural features on their surface behavior is analyzed through changes in surface properties, including effectiveness (pi(cmc)) and efficiency (PC(20)) of adsorption, the surface excess concentration (Gamma(max)) and the area per surfactant molecule at the air/water interface at surface saturation (A(min)). Thermodynamic properties, adsorption and micellezation of the prepared surfactant in addition to their biodegradability were investigated.