Chain-end functionalized polybutadiene polymers have widespread application in composite solid propellants (CSP). Curing of these polymers is effected using the reactions at the terminal groups with isocyanates or aziridines if the functional groups are hydroxyl or carboxyl respectively. The high toxicity of isocyanates and aziridines demands alternate cure methods. A facile reaction, devoid of any side reactions is the most desirable one. The large number of double bonds in polybutadienes is favorable for 1, 3-dipolar addition reaction with an azide to yield triazolines. The mechanistic aspects of the uncatalyzed and copper-mediated azide-alkene reaction have not been explored previously. The present study focuses on elucidation of the reaction using model compounds of polybutadiene namely trans 3-hexene, cis-3 hexene and 3-methyl pentene which mimic the microstructure of polybutadienes. The paper presents the elucidation of the mechanism using density functional theory (DFT) calculations, detailed reaction pathway and its experimental validation using Fourier transform infrared (FTIR) spectroscopy and 13 C nuclear magnetic resonance (NMR) spectroscopy. DFT studies indicate that the activation barrier of 63.8 to 85 kJ/mol for the uncatalyzed reaction. In the copper catalyzed reaction, it diminishes to the range of 18.1 to 33.0 kJ/mol. The thermal decomposition aspects of the cured triazoline system were evaluated using thermogravimetric-mass spectrometer (TG-MS). The binder undergoes single stage decomposition in the temperature regime of 278 C-534 C which is lower than that reported for polyurethane-polybutadienes. The decomposition reaction yields more volatile products like nitrogen, carbon dioxide, 1,4 butadiene and 4-vinylcyclohexene, conducive for propellant applications.