Catalyst‐Free Preparation of a High‐Strength Glycidyl Azide Polymer‐Based Polytriazole Curing System

ABSTRACT To further enhance the toughness of glycidyl azide polymer (GAP)‐based polytriazole (GAP‐PTA) elastomers, this work provided a novel multifunctional alkyne‐terminated curing agent with high reactivity suitable for click chemistry reaction and analyzed the influence of the amount of the curing agent on the mechanical properties of GAP‐PTA networks. First, the curing agent tri(prop‐2‐yn‐1‐yl) hexane 1,6‐diyldicarbamate trimer was synthesized in a laboratory via a catalyst‐free addition reaction between NCO from hexamethylene diisocyanate trimer and OH from propargyl alcohol. The chemical structures were characterized by Fourier transform infrared analysis and nuclear magnetic resonance spectroscopy. Second, esterified GAP as a prepolymer was cured with different amounts of the curing agent to prepare a series of GAP‐PTA elastomers, whose mechanical properties, microstructures, and thermal properties were investigated via uniaxial tensile testing, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), respectively. When the stoichiometric ratio of N 3 /CCH was 1.5, the GAP‐PTA networks exhibited prominent mechanical performance, with a tensile strength of 91.3 MPa and elongation at break of 31.8%. Although tensile strength was maintained, the elongation at break increased by 200% compared with data derived from previous studies. SEM indicated that the overall matrix structure of the GAP‐PTA elastomers had no pores, and the microstructures mainly exhibited brittle fracture. TGA showed that the GAP‐PTA elastomers, whose initial decomposition temperatures were above 200°C, had excellent thermal stability. This work can provide guidance for the preparation of high‐strength GAP‐PTA networks.