RAFT synthesis of triply responsive poly[-[2-(dialkylamino)ethyl]acrylamide]s and their -substitute determined response

The thermo- and pH/CO 2 -responsive poly[ N -[2-(dialkylamino)ethyl]acrylamide]s containing a polyacrylamide backbone but different N -substitutes of dialkylamine were synthesized and their solution properties were comparatively checked. A controllable RAFT synthesis of poly[ N -[2-(dialkylamino)ethyl]acrylamide]s was achieved when a typical trithiocarbonate containing an easily cleavable R group was employed. The RAFT polymerization rate decreases with the increasing C-number in the N -substitutes. The thermo- and pH/CO 2 -responsive property of poly[ N -[2-(dialkylamino)ethyl]acrylamide]s is firmly correlative to the N -substitutes. With the C-number in the R-substitute increasing, the solution properties of poly( N -[2-(dialkylamino)ethyl]acrylamide)s undergo a soluble-to-thermoresponsive-to-insoluble evolution, and the critical pH of poly[ N -[2-(dialkylamino)ethyl]acrylamide]s gradually decreases. The dialkylamine moieties in the poly[ N -[2-(dialkylamino)ethyl]acrylamide]s lead to a characteristic CO 2 -response during CO 2 /N 2 bubbling. The present study reveals the structure-dependent solution properties of the thermo- and pH/CO 2 -responsive poly[ N -[2-(dialkylamino)ethyl]acrylamide]s, and these multistimuli-responsive polymers are believed to be very useful due to the controllable RAFT synthesis and tunable solution properties. The thermo- and pH/CO 2 -responsive poly[ N -[2-(dialkylamino)ethyl]acrylamide]s containing a polyacrylamide backbone but different N -substitutes of dialkylamine were synthesized and their solution properties were comparatively checked.