The effect of filler loading on the mechanical properties of crosslinked triazole polymers obtained by polymerization of E300 dipropiolate (1) with diazide (2) obtained from tetraethylene glycol using tetraacetylene functionalized crosslinker (3) was studied systematically. Aluminum (10 14 mu m) was used as the primary filler during the formulations; the effect of secondary fillers such as aluminum (<75 mu m), NaCl (45-50 and 83-105 mu m) was studied with the increase in the total filler loading. The modulus of the aluminum-filled crosslinked triazole polymers increases with the increase in the filler content while using either particle sized aluminum powder. The use of Al (particle size <75 mu m) and NaCl (particle size 45-50 mu m and 83-105 mu m) as secondary or additional fillers while using aluminum (10-14 mu m) as the main filler, has a diminishing effect on the modulus and strain of the crosslinked triazole polymers. Triazole polymers described herein have the ability to wet and adhere to large quantities of these inorganic salts and thus maintain mechanical properties of the composite comparable to typical polyurethane elastomeric matrices, regardless of the chemistry of the particulate filler, which imparts an important and necessary binder characteristic for energetic composites. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 121-127, 2010