Facile Preparation and Properties of Crosslinked Copolyether Elastomers with 1,2,3‐Triazole and Urethane Subunit via Click Polymerization

• Published in: ChemistryOpen (Weinheim) 2019-05, Vol.8 (5), p.571-579
• Main Authors: Zhang, Qian, Liu, Ning, Mo, Hongchang, Lu, Xianming, Wang, Yao, Xu, Minghui, Shu, Yuanjie
• Format: Article
• Language: English
• Subjects: 1,3-Dipolar cycloaddition reactions; ATUPET; Carbon; Copolymers; Crosslinking; Curing; Curing agents; Dependence; elastomer; Elastomers; Elongation; Ethylene oxide; Formulations; Fourier transforms; Gas flow; Hydrogen; Hydrogen bonding; Isocyanates; Mechanical properties; NMR; Nuclear magnetic resonance; Polyethylene glycol; Polymers; Prepolymers; Propellant binders; Solvents; Stoichiometry; Structural analysis; Tensile strength; Tetrahydrofuran; Thermal analysis; thermal behavior; Triazoles
• ISSN: 2191-1363; 2191-1363
• DOI: 10.1002/open.201900065

An azide terminated ethylene oxide‐tetrahydrofuran copolymer with urethane segments (ATUPET) as a novel binder pre‐polymer, has been prepared through ethylene oxide‐tetrahydrofuran random copolymer (PET) end‐capping modification via one‐pot method. The structure characterization of the modifier has been analyzed by FTIR, 1H NMR, 13C NMR and GPC. In comparison with PET, ATUPET has a slightly higher viscosity because it has additional hydrogen bonding interaction generated by the urethane in ATUPET. Triazole cross‐linked elastomers based on ATUPET with various functional molar ratios were prepared using tripropargylamine as a curing agent and cross‐linker. Mechanical properties indicate that the modulus E and tensile strength σb exhibit a parabolic dependence with the increase in R. At around the stoichiometric ratio, the modulus E and tensile strength σb reach a maximum and the elongation at break exhibit an acceptable value at the same time. Swelling tests demonstrate that the apparent cross‐linking densities (N0) have a maximum value at the stoichiometric ratio. Thermal analysis shows that the ATUPET prepolymer and its polytriazoles elastomers exhibit a satisfactory stability. The results demonstrated that ATUPET might be a promising polymeric binder for future propellant formulations especially in the field of isocyanate‐free curing technology. Click and cross: A novel azide terminated ethylene oxide‐tetrahydrofuran copolymer with urethane segments (ATUPET) has been prepared through a facile method. The elastomers based on ATUPET exhibited improved mechanical properties and satisfactory thermal stability, which indicated that this might be a promising polymeric binder for future propellant formulations especially in the field of isocyanate‐free curing technology.