Green Synthesis of Waterborne Polyurethane for High Damping Capacity

Damping materials have application prospects in shock absorption and noise reduction due to their ability to convert vibration into other forms of energy dissipation. Although there have been tremendous attempts to prepare materials with high damping performance, it is still a challenge to fabricate materials with excellent mechanical properties and stability while maintaining a high energy dissipation capacity. Herein, damping materials of reinforced waterborne polyurethane by adjusting the ratio of soft and hard segments is reported. As the content of hard segments increases, the content of hydrogen bonds interaction between segments increases and the phase boundaries on the microscopic morphology form which obviously enhances the damping capacity. The ultimate samples exhibit a damping capacity of more than 90% and a toughness of 14.8 MJ m–3, maintaining good toughness while exceeding the damping capacity of the most reported materials. The damping mechanisms are summarized into three aspects, the frication among soft segments, the destruction of hydrogen bonds, and the interface friction between soft and hard domains. This work paves an avenue for the application of waterborne polyurethane materials in kinetic energy buffering and impact reduction.