New thermo-sensitive graft copolymers based on a Poly(N- isopropylacrylamide) backbone and functional polyoxazoline grafts with random and diblock structure

New thermo-sensitive functionalized graft copolymers characterized by a poly(N-isopropylacrylamide) backbone and grafts containing 2-ethyl-2-oxazoline and 2-(2-methoxycarbonylethyl)- 2-oxazoline units were synthesized. The conformation transition temperatures of the graft copolymers could be modified by variation of the molar composition in the side chain, by different side chain structure (random distribution of both oxazolines vs. diblock structure) and by hydrolysis of the methylester to the acid form. Graft copolymers with long functional oxazoline side chains allowed the stabilization of aggregates above the phase transition temperature of the backbone until the LCST of the side chain. The temperature window allowing for the formation of stable aggregates was widened with acid functions in the corona.