摘要
Polyethylene glycol(PEG)with different chains was used to modify epoxy asphalt.Molecular models of PEG⁃modified epoxy asphalt were developed using molecu⁃lar simulations(MS).The thermodynamic and mechanical properties of PEG⁃modified epoxy asphalt were analyzed,and its toughening mechanisms were explored.A method based on the Dijkstra algorithm was proposed to evaluate ep⁃oxy asphalt crosslinked networks.The results show that the introduction of PEG chains into epoxy asphalt can lower the glass transition temperature and enhance its toughness be⁃cause of the extended length of the PEG chains,which can in⁃crease the free volume and improve the mobility of the epoxy resin in the epoxy asphalt.The crosslinked network quantita⁃tive evaluation method based on the Dijkstra algorithm can ef⁃fectively evaluate the distribution of epoxy asphalt crosslink⁃ing bonds,providing further explanation of the toughening mechanism of PEG⁃modified epoxy asphalt.The feasibility of designing and screening epoxy asphalt materials by MS is verified,and a guide for toughening mechanism research of epoxy asphalt at the molecular level is provided.
采用不同链长的聚乙二醇(PEG)对环氧沥青进行改性,基于分子模拟技术构建了PEG改性环氧沥青的分子模型。分析了PEG改性环氧沥青的热力学和机械性能,探讨了PEG改性环氧沥青的增韧机制,并开发了一种用于评价环氧沥青交联网络的算法。结果表明,引入PEG链可降低环氧沥青的玻璃化转变温度并增强其韧性,这归因于PEG链的延长可增加自由体积并改善环氧沥青中环氧树脂的流动性。采用基于Dijk-stra算法提出的交联网络定量评价方法,可以有效评估环氧沥青交联点的分布,有利于理解PEG改性环氧沥青的增韧机制。验证了采用分子模拟进行设计和筛选环氧沥青材料的可行性,并为分子水平上的环氧沥青增韧机理研究提供了指导。
基金
The Major Science and Technology Project of Nan⁃jing(No.202209012)
the Postgraduate Research and Practice Innova⁃tion Program of Jiangsu Province(No.KYCX22⁃0277).
