Internal plasticized glycidyl azide polyethers for solid propellant binders

Copolymers of epichlorohydrin and n-alkyl substituted oxiranes were synthesized by the application of cationic ring-opening polymerization (CROP) using a BF3 complex as a catalyst and 1,4-butanediol as a co-initiator, followed by a subsequent azidation. The introduction of nonpolar side chains shows an internal plasticizing effect by lowering the glass-transition temperatures (Tg) and the viscosities of the synthesized copolymers compared to a commercial sample of GAP. Due to the improved low temperature properties of the prepolymers, they are interesting candidates for the formulation of composite rocket propellants.