Yu Caihua, Hu Kui, Yang Qilin, Wang Dandan, Zhang Wengang, Chen Guixiang, Kapyelata Chileshe
College of Civil Engineering, Henan University of Technology, Zhengzhou 450001, China.
School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
Polymers (Basel). 2021 May 20;13(10):1658. doi: 10.3390/polym13101658.
Carbon nanotubes (CNTs) can improve the storage properties of modified asphalt by enhancing the interfacial adhesion of recycled polyethylene (RPE) and base asphalt. In this study, the interaction of CNT/RPE asphalt was investigated using molecular dynamics simulation. The base asphalt was examined using a 12-component molecular model and verified by assessing the following properties: its four-component content, elemental contents, radial distribution function (RDF) and glass transition temperature. Then, the adhesion properties at the interface of the CNT/RPE-modified asphalt molecules were studied by measuring binding energy. The molecular structural stability of CNTs at the interface between RPE and asphalt molecules was analyzed through the relative concentration distribution. The motion of molecules in the modified asphalt was studied in terms of the mean square displacement (MSD) and diffusion coefficient. The results showed that CNTs improved the binding energy between RPE and base asphalt. CNTs not only weakened the repulsion of RPE with asphaltenes and resins, but also promoted the interaction of RPE with light components, which facilitated the compatibility of RPE with the base asphalt. The change in the interaction affected the molecular motion, and the molecular diffusion coefficient in the CNT/RPE-modified asphalt system was significantly smaller than that of RPE-modified asphalt. Moreover, the distribution of the asphaltene component was promoted by CNTs, resulting in the enhancement of the storage stability of RPE-modified asphalt. The property indexes indicated that the storage stability was significantly improved by CNTs, and better viscoelastic properties were also observed. Our research provides a foundation for the application of RPE in pavement engineering.
碳纳米管（CNTs）可以通过增强再生聚乙烯（RPE）与基质沥青的界面粘附力来改善改性沥青的储存性能。在本研究中，采用分子动力学模拟研究了CNT/RPE沥青的相互作用。使用12组分分子模型对基质沥青进行了研究，并通过评估以下性能进行了验证：其四组分含量、元素含量、径向分布函数（RDF）和玻璃化转变温度。然后，通过测量结合能研究了CNT/RPE改性沥青分子界面处的粘附性能。通过相对浓度分布分析了RPE与沥青分子界面处CNTs的分子结构稳定性。从均方位移（MSD）和扩散系数方面研究了改性沥青中分子的运动。结果表明，CNTs提高了RPE与基质沥青之间的结合能。CNTs不仅减弱了RPE与沥青质和树脂的排斥力，还促进了RPE与轻质组分的相互作用，这有利于RPE与基质沥青的相容性。相互作用的变化影响了分子运动，CNT/RPE改性沥青体系中的分子扩散系数明显小于RPE改性沥青。此外，CNTs促进了沥青质组分的分布，从而提高了RPE改性沥青的储存稳定性。性能指标表明，CNTs显著提高了储存稳定性，还观察到了更好的粘弹性性能。我们的研究为RPE在路面工程中的应用提供了基础。
