Non‐Ionic Homo‐ and Copolymers with H‐Donor and H‐Acceptor Units with an UCST in Water

Abstract A well‐studied example of a thermoresponsive polymer is PNiPAAm, which exhibits a sharp coil‐to‐globule transition in water at its LCST. A study relating to the missing counterpart of LCST polymers is presented: N ‐acryloylglycinamide (NAGA) homopolymer and copolymers from NAGA and N ‐acetylacrylamide (NAcAAm) that show a sharp UCST (where the sharpness depends on the composition). The polymers were synthesized by free‐radical copolymerization and the copolymerization parameters were determined by the method of Kelen‐Tüdös. The UCST was investigated by turbidimetry, regarding the influence of the copolymer composition, the polymer concentration and the addition of electrolytes. magnified image