Investigation the Effect of Chain Extender on Physical, Mechanical and Energetic Properties of Thermoplastic Polyurethane Binder

Polyurethanes are the most well-known polymers used as a binder in high energy material. Polyurethanes are generally synthesized by the reaction of diisocyanates, polyols and a chain extender. Polyurethane elastomers have a two phase morphology consisting of hard and soft segments. Chain extenders are small diols or diamines that are inserted to the hard segment of polyurethane chain. Chemical structure of chain extender, the amount of chain extenders in polyurethane and processing condition can change the morphology and properties of the polymer through influencing on the intermolecular attractions between hard-hard and hard-soft segments of polyurethane. In this paper, the role and impact of various chain extender on the physical, mechanical and energetic properties of the thermoplastic polyurethane were investigated.