Bioengineering functional copolymers. XI. Copper(II)‐poly( N ‐vinyl‐2‐pyrrolidone‐ co ‐ N ‐isopropylacrylamide) macrocomplexes

A series of poly( N‐ vinyl‐2‐pyrrolidone‐ co ‐ N‐ isopropylacrylamide)s, poly(VP‐ co ‐NIPA) copolymers with different compositions were prepared by radical copolymerization of VP and NIPA in N,N′ ‐dimethylformamide at 65°C using 2,2′‐azobisisobutyronitrile as initiator. Cu(II)‐copolymer macrocomplexes were prepared by complexation of the copolymers with copper sulfate in aqueous solution at 40°C. The structure and composition of the copolymers, and the formation of coordinated Cu(II)‐complexes between amide VP units and Cu 2+ ions, were studied by FTIR spectroscopy, DSC and TGA‐DTG in addition to electrical conductivity. Studies on the relationship between composition and thermal behavior showed that the values of T g and T d of the copolymers and their coordinated macrocomplexes increased with increasing VP content. The copolymers predominantly show amorphous structure while their Cu(II)‐macrocomplexes show the presence of a crystalline phase. The conductive properties of the synthesized Cu(II)‐poly(VP‐ co ‐NIPA) complexes are also discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008