聚氨酯与稀释沥青相互作用的分子动力学模拟

Molecular dynamics simulation of the interaction between polyurethane and diluted asphalt

为从分子尺度深入了解聚氨酯与稀释沥青的相互作用,采用Materials Studio软件,分别构建沥青、聚氨酯、聚氨酯-稀释沥青共混模型,并验证模型准确性。基于分子动力学模拟,开展温度和聚氨酯掺量对稀释沥青内聚能密度、溶解度参数、相互作用能、力学性能的影响研究。结果表明:建立的沥青和聚氨酯分子模型较合理,能够表征沥青和聚氨酯真实特性;随着温度的升高,稀释沥青和稀释沥青-聚氨酯共混体系的内聚能密度均呈下降趋势;在[-10℃,100℃]范围内,聚氨酯添加物能够降低稀释沥青的内聚能密度,不同温度下降低幅度平均为15%;在60℃时,稀释沥青与聚氨酯的溶解度参数δ差值最小,各总相互作用能和范德华势能最大,体系最稳定;聚氨酯能够提高稀释沥青的力学参数,并且力学参数与聚氨酯的掺量呈正相关关系。研究对树脂改性冷补沥青混合料具有参考价值。

In order to deeply understand the interaction between polyurethane and diluted asphalt at the molecular level,Materials Studio software was used to construct asphalt,polyurethane and polyurethane-diluted asphalt blending models,and the accuracy of the models was verified.Based on molecular dynamics simulation,the effects of temperature and polyurethane content on the cohesive energy density,solubility parameters,interaction energy and mechanical properties of diluted asphalt were studied.The results showed that the established molecular models of asphalt and polyurethane were more reasonable and could characterize the characteristics of asphalt and polyurethane.With the increase of temperature,the cohesive energy density of diluted asphalt and diluted asphalt-polyurethane blends showed a decreasing trend.In the range of[-10℃,100℃],polyurethane additives reduced the cohesive energy density of diluted asphalt,with an average reduction of 15% at different temperatures.At 60℃,the solubility parameter δ difference between diluted asphalt and polyurethane was the smallest,the total interaction energy and van der Waals potential energy were the largest,and the system was the most stable.Polyurethane could improve the mechanical parameters of diluted asphalt,and the mechanical parameters were positively correlated with the content of polyurethane.The study has reference value for resin-modified cold patching asphalt mixture.