Synthesis of polytetrahydrofuran-polyethylene glycol copolymer by depolymerization method for use in Launch Vehicle

Rockets are used to carry satellites and other items into space. One of the main components of satellite launchers is its engine .The solid fuel rocket engine usually uses a composite propellant to achieve high thrust and impulse. Considering the stresses and pressures applied to the solid propellant during construction, maintenance, transportation and use, the solid propellant must have excellent mechanical properties. The solid propellant consists of polymer binder and solid load. which is responsible for maintaining and improving the mechanical properties of the binder. Propellant based on polyether is widely used in space and military industries. In this paper, the synthesis of one of the new polyethers used in the upper stages of satellite launchers (third stage of Minotaur) was investigated. Due to the progress in the field ofpolyether binder, copolymerized frompolytetrahydrofuran (PolyTHF) and polyethylene glycol (PEG) was introduced as a binder with excellent mechanical properties and more impulse than conventional propellants. Synthesis of PolyTHF and PEG copolymer is done by depolymerization method. In this method, in two simultaneous steps, PolyTHF is depolymerized using sulfuric acid as a catalyst, and in the next step, the depolymerized material reacts with the hydroxyl at the end of the PEG, and then two polymers are paired and a copolymer is formed The synthesized copolymer was characterized using various tests, which revealed that there is an almost equal amount of both polymers in the copolymer, as well as the molecular weight (Mn) of ۴۴۹۰ g/mol, which is useful for use in composite propellant.