Bio-based polyurethane/tannic acid composites with adjustable damping property enabled by constructing multiple sacrificial networks

Damping materials play a significant role in reducing vibrations and noise. Presently, polyurethane (PU) elastomers fabricated from renewable resources have attracted considerable attention in damping fields owing to their significant benefits towards sustainable development and green production. Bio-based PU (bio-PU) elastomer is successfully synthesized from bio-based poly (trimethylene ether) glycol and bio-based 1,5-pentamethylene diisocyanate. Tannic acid (TA) is then incorporated into the bio-PU elastomer to enhance the damping, mechanical, and thermal properties by constructing multiple sacrificial networks. Depending on the energy dissipation of sacrificial networks, the fabricated bio-PU/TAcomposites exhibit a mechanical strength of 16.0 MPa (4.9 times higher than that of the bio-PU elastomer), with a glass-transition temperature raised from −63.7 to −26.8 °C and tanδ_max enhanced from 0.50 to 0.91. In addition, the abundant polyphenolic structures of TA endowed bio-PU/TA composites with excellent ultraviolet absorption capability and high transparency. This work not only develops elastomers with excellent and controllable damping properties, but also has the potential to advance the sustainable growth of PU industry.