Vol.:(0123456789) Polymer Bulletin https://doi.org/10.1007/s00289-020-03440-9 1 3 ORIGINAL PAPER Superior improvement in thermo‑mechanical properties of polyurethane based on glycidyl azide polymer/ polyethylene adipate Yadollah Bayat 1  · Hasan Kashef Shandi 1  · Tayebe Khanlari 1 Received: 16 June 2020 / Revised: 20 October 2020 / Accepted: 23 October 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract In this study, to improve the thermo-mechanical properties of glycidyl azide poly- mer (GAP)-based elastomers, polyethylene adipate (PEA) with diferent molecular weights was successfully synthesized using a solvent-free method. GAP was syn- thesized by cationic ring-opening polymerization of epichlorohydrin and then azida- tion. The structure of PEA and GAP was characterized by FTIR, 1 HNMR, and GPC. The compatibility of GAP/PEA at various weight ratio blends was investigated by diferential scanning calorimetry. The result indicated GAP/PEA is compatible, and addition of PEA to GAP leads to the decrease in glass transition temperature. The copolyurethane elastomers were prepared by cross-linking GAP and PEA at various weight ratios using isophorone diisocyanate and N100 as curing agent. The thermo- mechanical properties were evaluated by dynamic mechanical analysis and tensile test. Based on the results, with increasing weight ratios of PEA, the copolyurethane elastomers displayed an increase in tensile strength (6.97 MPa) and elongation (792%) in comparison with GAP. Keywords Glycidyl azide polymer (GAP) · Polyethylene adipate (PEA) · Blending · Copolyurethane elastomer · Mechanical properties Introduction Solid composite propellants consist of oxidizers, metallic fuels, binders, plasticizer, and other additives [1–3]. Among these components, the binder plays an important role in binding the components of the propellant [4–6]. In the last decades, the use of polymeric binders including energetic functional groups in polymer backbones (such as nitro, azido, and difuoramine) [7, 8] instead of usual and inert binders * Yadollah Bayat y_bayat@mut.ac.ir 1 Faculty of Chemistry and Chemical Engineering, Malek Ashtar University of Technology, P.O. Box16765-3454, Tehran, Iran