Rheological Properties and Modified Mechanism of Polyurethane Solid-solid Phase Change Materials Modified Asphalt

Document Type

Article

Publication Date

1-20-2023

Department

Department of Civil, Environmental, and Geospatial Engineering

Abstract

To evaluate the potential of polyurethane solid-solid phase change materials (PUSSPCMs) as asphalt modifiers, the influence of PUSSPCMs soft segments on the rheological properties and mechanism of asphalt was investigated. Therefore, PUSSPCMs with different soft-segment mass fractions (P70, P75, P80, P85, and P90) and the corresponding PUSSPCMs modified asphalt were prepared as testing materials in this study. Temperature regulating properties, dynamic shear rheology (DSR), and bending beam rheology (BBR) tests were used to investigate the temperature regulation and rheological properties of PUSSPCMs modified asphalt, and the modified mechanism was analyzed by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and atomic force microscopy (AFM). The results show that PUSSPCMs modified asphalt exhibits better temperature-regulating properties than base asphalt, as well as greater deformation resistance and high-temperature performance, while low-temperature performance is lower. The temperature regulating properties and low-temperature performance of PUSSPCMs modified asphalt are greatly enhanced as the soft segment mass fraction increases, while the deformation resistance and high-temperature performance are correspondingly reduced. P90 asphalt has the best temperature-regulating properties and low-temperature performance, whereas P70 asphalt has the highest deformation resistance and high-temperature performance. PUSSPCMs have excellent heat storage-release properties, and P90 has a greater enthalpy and a lower initial temperature than P70. Furthermore, the enthalpy of PUSSPCMs is closely linked to the temperature-regulating properties of PUSSPCMs modified asphalt. In addition, there is no new functional group between the PUSSPCMs and asphalt, which means that it is a physical modification. As the soft segment mass fraction of PUSSPCMs increases, the "bee-like structure" of the asphalt expands, while the difference between the peripheral phase state and Young's modulus decreases. These are inextricably related to the high- and low-temperature performances of PUSSPCMs modified asphalt.

Publication Title

Zhongguo Gonglu Xuebao/China Journal of Highway and Transport

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