The double stimuli responsive water-soluble poly(urethane amine)s are prepared under supercritical carbon dioxide (scCO2) with renewable resourcescarbon dioxide and natural -amino acidsas the starting materials. The urethane content, which will decide on the thermosensitive behavior of poly(urethane amine)s, is regulated not only by the substituent on aziridine derivatives but also by the coordinated metallic ion of Salen-metal complexes as a catalyst. Interestingly, the thermosensitive reversibility is also changed through the application of Salen-metal complexes in the copolymerization reaction of CO2 with aziridine derivatives. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013