The mechanical properties of crosslinked polymers depend on their structural features, one of which is the functionality of the crosslinks in a polymer network. To study the effect of crosslink functionality (Phi) on the mechanical properties of 1,2,3-triazole polymers for potential application as rocket propellant binders, crosslinkers with different Phi's (3, 4, 6, 16, 32, and 64) were used in the polymerization. As the percentage of acetylenic groups provided by crosslinker was kept constant and the functionality of the crosslinker increased, the resulting polymer showed a higher modulus but a lower strain. Compared to traditional polyurethane binders, 1,2,3-triazole polymers showed comparable mechanical properties, although the stress and modulus tended to be lower and the strain capability tended to be greater for the triazole-linked rubbers. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 473-478, 2010