New methacrylic acid copolymers and their formation of complex coacervates with polyamines

The aqueous solution properties of both binary and ternary anionic copolymers such as lower critical solution temperatures (LCST) and their ability to form complex coacervates with polyethylenimines are studied. These copolymers are composed of varying ratios of the monomers methacrylic acid, poly(ethylene glycol) monomethylether monomethacrylate, and butyl methacrylate. Both the binary and ternary copolymers have LCST. Furthermore, complex coacervation has occurred upon addition of aqueous PEI to aqueous solutions of these copolymers. The onset of coacervation has occurred at different amine/carboxylic acid ratios for the different copolymers.