Polytriazole polyether elastomers with widely tunable mechanical properties: The role of network structure and crystallization behavior

The polytriazole polyether elastomers were prepared by the propargyl-terminated ethylene oxide-tetrahydrofuran [PTP(E-co-T)] prepolymer and the multi-azide group glycidyl ether with different curing parameter R. The relationship between the network structure, mechanical properties, and crystallization behaviors of the elastomers were investigated by swelling testing, tensile testing machine, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and in situ wide-angle X-ray scattering at 60, 20, and −40 °C, respectively. The mechanical properties of the polytriazole elastomers exhibited obviously different dependences on R values at different testing temperatures. At 60 and 20 °C, with the increase of R, the tensile stress at breaking gives a parabola going downwards with a maximum at R = 1.1. However, at −40 °C, the stress exhibited an analogous parabola going upward with a minimum at R = 1.1. The DSC and WAXD results indicated that at 60 and 20 °C, the polytriazole elastomers was amorphous, but at −40 °C, the polytriazole elastomers were crystallizable and the crystallization capability of the polytriazole elastomers are also observed. Therefore, it can be inferred that at 60 and 20 °C, the mechanical properties of the polyether polytriazole elastomer depend on completeness of the network structures, while the crystallization behavior of the polytriazole elastomers induces its different mechanical properties at −40 °C.