Synthesis of Waterborne Polyurethane–Acrylate Composite Emulsions Containing Two Hydrophilic Chain Extenders to Achieve their Potential Low Temperature Damping Applications

Damping coatings with low temperature resistance on high-speed rail trains had been designed through the establishment of a polymer cross-linked network and the introduction of dimethylolpropionic acid and sodium 2-[(2-aminoethyl) amino] ethanesulfonate as a hydrophilic chain extender. The phase separation behavior and hydrogen-bonded interactions in composite materials effectively enhanced the hydrophobicity, film-forming properties, and damping performance. The phase separation behavior plays a dominant role. The damping peaks of the samples are saddle-shaped, and the peaks of the saddle-shaped saddle bottom also meet the requirements of vibration and noise reduction engineering technology. The effective damping temperature range (tan δ > 0.3) was broadened to 114.7 °C. The prepared waterborne polyurethane–acrylate composite emulsions can be applied to the damping of complex structural surfaces and are environmentally friendly. The strategy of regulating the phase separation behavior of materials to enhance the damping performance of materials also offers a new method for the synthesis of high-performance damping coatings.