Effect of Partial Quaternization on the Aqueous Solution Properties of Tertiary Amine-Based Polymeric Surfactants: Unexpected Separation of Surface Activity and Cloud Point Behavior

Low degrees of Me iodide quaternization eliminates the LCST behavior of 2-(Dimethylamino)ethyl methacrylate-2-(diethylamino)ethyl methacrylate diblock copolymers (DMA-DEA) and significantly extends the pH (and temp.) range for colloidally stable micelles. Similar results were previously reported for fully quaternized DMA-DEA diblock copolymers, but these latter materials are poor surfactants since unfavorable electrostatic interactions lead to poor packing efficiencies at the air-water interface. In contrast, in the present study lightly quaternized diblock copolymers exhibit similar surface activities to the un-quaternized diblock copolymer precursor; thus, judicious control of the degree of quaternization unexpectedly allows fine-tuning and optimization of the aq. soln. properties of these new cationic polymeric surfactants. on SciFinder (R)