Preparation and molecular dynamics study of polyurethane damping elastomer containing dynamic disulfide bond and multiple hydrogen bond

• The damping and mechanical properties are balanced by the synergy of dynamic disulfide bond and hydrogen bond. • The relationship between structure and performance was discussed by combining BDRS and microphase separation morphology. • The molecular dynamics behavior of the material was discussed in detail by mechanical relaxation, dielectric relaxation and rheological spectra. Using damping materials is an effective measure to control vibration and noise, which is widely used. However, it is relatively difficult for polymer damping materials to find a balance between damping and mechanical properties. Herein, a polyurethane is designed containing dynamic disulfide bonds and hydrogen bonds of different strength to address the dilemma. The polyurethane is endowed with good damping and mechanical properties (effective damping temperature range of 117 °C and a tensile strength of 14.98 ± 0.50 MPa). The molecular dynamics were studied by combining dynamic mechanical analysis (DMA) and broadband dielectric relaxation spectroscopy (BDRS). The microphase separation morphology and degrees of separation were used to help explain molecular dynamics. The segmental motion of soft phase becomes difficult in the glass-transition temperature (Tg) and faster in a high temperature with increasing 2, 2′-Dithiodibenzoic acid (DTSA) contents. These results explain the mechanism improving damping performance and provide some references for designing damping materials in the future.