Characterization of temperature-induced phase transition of polymer complex composed of poly(N,N-dimethylamino)ethyl methacrylate and poly(ethylacrylamide) by 1H-NMR relaxation time measurement

A new temperature-responsive polymer system with transitions resulting from both polymer–water and polymer–polymer interactions has been demonstrated using the mixture of poly(N,N-dimethylamino)ethyl methacrylate (DMAEMA) and poly(ethylacrylamide) (EAAm). The structure and dynamic motions of the mixture of poly(DMAEMA) and poly(EAAm) were studied in comparison with that of poly(DMAEMA-co-EAAm) by 1H spin–lattice relaxation time. The T1 values corresponding to two peaks of the poly(DMAEMA-co-EAAm) at 15°C have long relaxation times relative to the mixture of poly(DMAEMA) and poly(EAAm). This suggests that there exist the structural difference in the temperature-induced phase transition between poly(DMAEMA-co-EAAm) and the mixture of poly(DMAEMA) and poly(EAAm).