Effect of evaporation temperature on evaporative residue properties of waterborne polyurethane modified emulsified asphalt

Abstract In recent years, waterborne polyurethane (WPU) modified emulsified asphalt has attracted much attention. The conventional property of WPU-modified emulsified asphalt (WPU-MEA) is usually measured by using the evaporative residue obtained at high temperatures. In this work, WPU-MEA was prepared and the influence of evaporative temperature on the conventional performances (softening point, penetration, ductility) of the residue of WPU-MEA was investigated. Fourier Transform Infrared Spectroscopy (FTIR) and Fluorescence microscope (FM) were used to analyze the chemical structure and morphology of the evaporative residues. It was found that the evaporation dehydration temperature has a significant influence on the property of the evaporation residue of WPU-MEA. The evaporative residue performance of WPU modified asphalt was better at an evaporation temperature of 110°C, and the three conventional properties were significantly improved. Upon increasing the evaporation temperature, the conventional properties of WPU-MEA continue to decrease. As the evaporation temperature is 190°C, the conventional property of the residue is close to that of unmodified emulsified asphalt. Considering the performance index of WPU-MEA, the optimal evaporation temperature should be determined in the characterization of residue performance. This study has a guiding significance for the development of polyurethane-modified asphalt materials.