Doctor of Philosophy, Case Western Reserve University, 2014, Chemical Engineering

Polymeric surfactants attracted considerable attention in recent years for applications such as personal care product and stabilization of emulsions and suspensions. The characteristic properties of polymeric surfactants originate from the formation of aggregates through the association of the hydrophobic alkyl chains in aqueous solution, within a narrow concentration range. The aggregates are called micelles, and the narrow concentration range above which micelles are formed in the solutions is called the critical micelle concentration (cmc),. The characteristics of micelles are easily controlled by changing the solution conditions such as temperature, concentration and ionic strength, and by changing the surfactant properties such as chain length, hydrophobic volume and head group area. In present work, a novel platform of anionic polymeric surfactants, poly(4HBA-oca-Na+), poly(4HBA-dea-Na+), and poly(4HBA-doa-Na+), has been synthesized by polymerizing benzoxazine monomers that are synthesized by reacting an aliphatic amine of variable chain length (C8, C10 and C12), with 4-hydroxybenzoic acid and paraformaldehyde. The structures of the monomers and polymeric surfactants are confirmed by NMR and FTIR. The ring-opening polymerization and thermal behavior of the benzoxazine monomers are studied by DSC and TGA. Size exclusion chromatography (SEC) coupled with Viscotek triple detection technique is used to characterize the molecular weight distribution of polybenzoxazine surfactants. The influence of the structure on the surface activity is investigated by measuring the surface tension of aqueous solutions of the polymeric surfactants using the Wilhelmy plate method. The tensiometry results indicate that the adsorption at the air/water interface is similar for the octylamine, decylamine and dodecylamine-based surfactants. Increasing the alkyl chain length from C8 to C12 does not significantly affect the surface tension at the critical micelle concentration ( (open full item for complete abstract)

Committee: SYED QUTUBUDDIN (Advisor); DANIEL LACKS (Committee Member); MOHANN SANKARAN (Committee Member); HATSUO ISHIDA (Committee Member) Subjects: Chemical Engineering