Inserting urethane into 1,2,3‐triazole click‐cured solid propellant binder to form microphase separation and enhance mechanical and combustible performances

Abstract

Huisgen‐click curing systems are widely used in solid propellant binders due to their low humidity sensitivity and mild reaction conditions. However, the rigid triazole rings from the Huisgen‐click reaction decrease the molecular moving ability and increase decomposition temperature, lowering the mechanical and combustion performance. Thus, we bonded the Huisgen‐click system and polyester binders with urethane, forming microphase separation and improving chemical stability. The results show that the elongation at break, tensile strength, and Young's modulus of the binders increase by 533.3%, 201.2%, and 1263.9%, respectively. Furthermore, the urethane reduces the thermal resistance index of the binders from 191.2 to 179.2°C, which means better combustion performance. Further mechanism study reveals that the urethane leads to microphase separation, which aggregates the hard segments and weakens their restriction effect on the molecular motion of polyether. Such a microphase separation brings comprehensive improvement in the mechanical properties of the solid propellants and probably can be used in other multi‐component systems of energetic materials.