Synthesis and characterization of novel polytriazoleimides by CuAAC step-growth polymerization

Cu (I)-catalyzed 1,3-dipolar cycloaddition step-growth polymerization was exploited in the synthesis of a novel class of polytriazoleimides. The polymerization with diazides and imide-containing dialkynes was readily carried out under mild conditions. The chemical structures of the resulting novel polyimides were characterized by Fourier transform infrared and nuclear magnetic resonance. These polymers exhibited good solubility in common polar organic solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, dimethylformide and dimethylsulfoxide. The flexible polytriazoleimide films were easily prepared from homogeneous polyimide solutions. The films had good mechanical properties with tensile strengths of 76.2–92.4 MPa as well as elongations at breakage of 4.8–6.9%. The resulting polytriazoleimide films showed a glass transition temperature of 221–254 °C and a decomposition temperature (at 5% weight loss) of 365–377 °C in nitrogen. A series of new 1,2,3-triazole-containing polytriazoleimides was synthesized by the copper-catalyzed click polymerization of azide–alkyne cycloaddition. The click polymerization of imide-containing dialkynes with the diazide could produce new polymers with imide and triazole units in the main chain.The polytiazoleimides obtained, with inherent viscosities of 0.39–0.58 dl g −1 , had good solubility in polar solvents and could be cast into transparent, tough and flexible films. These novel polytriazoleimide films exhibited good thermal stability and mechanical properties