Thermoresponsive poly(2-oxazoline) homopolymers and copolymers in aqueous solutions studied by NMR spectroscopy and dynamic light scattering

•We studied thermoresponsive poly(2-oxazoline) homopolymers and copolymers in D2O.•We used NMR spectroscopy combined with dynamic light scattering.•The phase transition of PEOx homopolymers is irreversible on molecular level.•Phase transition of P(EOx-grad-MOx) copolymers is very broad and reversible.•Two types of water, free and bound, with slow exchange were detected at transition.