AbstractTo enable future environmentally friendly access to space by means of solid rocket propulsion a viable replacement to the toxic ammonium perchlorate (AP) oxidizer is needed. Ammonium dinitramide (ADN) holds great promise as a green replacement. Unfortunately compatibility issues with many polymer binder systems have hampered the development of ADN‐based formulations. Herein we present proof‐of‐concept of a polymer cure system based on hyperbranched copolymers of 3‐ethyl‐3‐(hydroxymethyl)oxetane (TMPO) and tetrahydrofuran (THF). The partly alkyne‐functionalized macromolecules were synthesized in a one‐pot procedure. TMPO and THF are found to polymerize in exact ratios, indicating a kinetically controlled buildup of nonrandom composition copolymers. Several of the materials show excellent compatibility with ADN, and rapid curing of the energetic polyglycidyl azide polymer (GAP) have been demonstrated through 1,3‐dipolar cycloaddition at 75°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011