Properties of new cationic amphiphilic polymers in hydro-alcoholic media

BACKGROUND: Following our recent synthesis and characterization of three new families of cationic amphiphilic polymers with great structural variability, this paper reports their physical chemical properties in aqueous media in relation to their chemical structure. These amphiphilic polymers are comb poly(meth)acrylamides laterally substituted by groups containing a quaternary ammonium site and hydrophobic n‐alkyl side chains with variable lengths. RESULTS: Viscometry first showed that these polymers display typical polysoap behaviour in hydro‐alcoholic mixtures. Fluorescence spectrometry was then used to characterize the corresponding intramolecular association with two complementary fluorescent probes. In addition to confirming macromolecular folding, pyrene provided information about the probe local environment polarity whereas a molecular rotor gave interesting complementary information about the compactness of the corresponding nano‐domains. CONCLUSION: It was shown that increasing the length of the n‐alkyl side chain induced much better polysoap properties whereas increasing the size of the spacer between the two polar amide and ammonium groups and the presence of a methyl side group had the greatest impact on the nano‐domain characteristics. Copyright © 2009 Society of Chemical Industry