The polyurethane (PU) modified asphalt prepared by melting method has poor thermal storage stability and the PU used is normally synthesized from non-renewable petrochemical resources. This paper aims to explore the feasibility of preparing environment-friendly PU and using it to enhance asphalt properties. Environmental-curable CO 2 -based PPC-PU and ordinary BDO-PU was prepared with poly propylene carbonate diol (PPC) and Butanediol (BDO), respectively. Fourier transform infrared spectroscopy and thermogravimetric analysis were used to examine their chemical compositions and thermal characteristics. Then, these two types of PU were used to modified asphalt and the chemical functional groups, microstructure, storage stability, viscosity, low temperature, and high temperature properties of various modified asphalts were tested. The findings revealed that the prepared PPC-PU and BDO-PU had good thermal stability and the decomposition temperature was above 200 °C. PPC-PU modified asphalt can be gradually cured at natural environment to form a crosslinking network, and the curing rate can reach 86.23% in 15 days. In addition to the low temperature performance, other properties of PPC-PU modified asphalt were gradually improved with the extension of curing time. Compared with BDO-PU modified asphalt, PPC-PU modified asphalt has superior storage stability, low temperature, and high temperature properties. It is concluded that the environmental-curable PPC-PU can improve performance of asphalt while consuming CO 2 . This research offers a fresh concept for producing of green PU modified asphalt.
The oxime-urethane group can undergo dynamic reversible reaction at room temperature, which can endow polyurethane (PU) with self-healing ability at ambient temperatures. This study prepared CO 2 -based PU containing oxime-urethane groups and introduced it into asphalt to enhance the self-healing performance of asphalt at room temperature. Firstly, the chemical structure , self-healing performance, and thermal stability of the prepared PU and ordinary PU were characterized. Then, the two types of PU were sheared in asphalt to prepare PU modified asphalts, the chemical characteristics and microstructure of the modified asphalts were characterized. Finally, the healing performance of different asphalts at room temperature was characterized. The results indicated that the prepared self-healing PU had good thermal stability and exhibited rapid self-healing performance at room temperature. After 6 h of healing, the maximum tensile strength can recover to 88.78% of its initial value . Self-healing (S-PU) was successfully introduced into asphalt system without decomposition, but due to the role of intermolecular hydrogen bond and dynamic covalent bond of PU, its dispersion in asphalt was poor. The addition of S-PU can significantly enhance the self-healing capability of asphalt at room temperature. This study provides a new idea for the preparation of green PU modified asphalt containing dynamic covalent bond.
危险品化学品经营许可证（带存储）