含水环境高聚物注浆材料交联过程与微观结构演变模拟

Simulation of Crosslinking Process and Microstructure Evolution of Polymer Grouting Material in Watery Environments

摘要:

为了研究在有水环境下注浆时水分子参与交联反应对高聚物注浆材料交联过程和微观结构特性的影响，构建了具有不同水分子质量分数的交联聚氨酯模型，采用分子动力学模拟方法，计算了不同含水量体系的参与交联反应的水分子数量、玻璃转变温度和自由体积，并提出一种计算交联分布均匀度的方法。结果表明：随着含水量增加，参与交联反应的水分子数先增大后趋于稳定，这是因为水分子团簇的体积随着水分子质量分数增加不断增大，限制了水分子参与交联反应。含水量越高，交联聚氨酯的玻璃转变温度越低，自由体积越小。水分子参加交联改善了体系的交联分布均匀性，含水量越高，体系的交联反应分布越均匀。研究结果可为有水环境下高聚物注浆材料反应过程和性能评价以及工程应用中高聚物注浆材料的设计研发提供理论参考。

Abstract:

To address the influence of water molecules participating in the crosslinking reaction on the crosslinking process and microstructure characteristics of polymer grouting material in watery environments， cross-linked polyurethane models with different water molecule mass fractions were constructed and molecular dynamics simulations were performed to calculate the number of water molecules participating in the crosslinking reaction， glass transition temperature， and free volume of systems with different water molecule mass fractions. Additionally， a method for calculating the uniformity of crosslinking distribution was proposed. The results show that as the water content increases， the number of water molecules participating in the crosslinking reaction first gradually increase and then stabilize， because the volume of water molecule clusters increases with the increase of water molecule mass fraction， which limits the participation of water molecules in crosslinking reaction. With higher water content， the glass transition temperature of cross-linked polyurethane is lower and the free volume is smaller. Water molecules participating in the crosslinking reaction improve the uniformity of crosslinking distribution in the model. As the water content increases， the crosslinking distribution of the model becomes more uniform. The current results will provide valuable theoretical reference for understanding the reaction process and evaluating the performance of polymer grouting materials in watery environments， as well as for the design and development of these materials in engineering applications.