橡胶基有机杂化阻尼材料中氢键网络的分子动力学模拟及优化设计

Rubber-based damping materials have been widely used in precision machine, mechanical absorber and submarine noise elimination due to the unique viscoelastic properties of polymer materials. The conventional methods for the designs of the rubber materials are mainly dependent on the empirical experiences and masses of experiments. However, the molecular simulation which can greatly reduce the cost and tedious experimental processes as well as forecast the performances, has become a new materials research attempt named as the third method along with scientific experimental and theoretical methods. As a feasible route to design the experiment, the molecular dynamics (MD) simulation can explain the phenomenon, set up the theory, and elucidate the fundamental mechanisms from the molecular level. In this research, the MD simulation was used to study the hydrogen-bond networks of rubber-based organic hybrid damping materials in detail as well as to optimize the materials design. By constructing the proper models for different rubber/ small organic molecules, MD simulation can be used to calculate the glass transition temperature (Tg), observe the formation of hydrogen-bonds, investigate the number of hydrogen-bonds, characterize the changes of hydrogen-bond interactions, forecast damping performance, and optimize the mass ratio of rubber/ small organic molecules. Moreover, a series of experiments were used to validate the simulation results. Through both MD simulation and experimental methods, we expect to establish the correlations between the hydrogen-bond network microstructures and the mechanical performances, and to sum up the optimum design rules of rubber-based damping materials. Such correlations are expected to provide a theoretical guidance for the design of rubber-based organic hybrid damping materials, and to create a novel method which combines the computer simulation technology with the materials optimization design.

橡胶基阻尼材料利用高分子的粘弹性进行阻尼减震，在精密仪器、机械减震、舰艇消声等领域得到广泛应用。传统橡胶基阻尼材料的制备多依赖经验和具体实验，而目前分子模拟已成为与实验科学、理论科学并列的第三种材料研究方法，可极大地降低成本及减少繁琐的试验过程，提供可行性实验设计方案并通过模拟解释现象、建立理论、探讨机理。本研究拟采用分子动力学模拟方法对橡胶基有机杂化阻尼材料的氢键网络进行详细描述和优化设计，创建不同橡胶基/极性小分子模型，模拟其玻璃化转变温度范围，观察氢键的形成过程、数量多寡、多重相互作用的能量变化等特性，对阻尼性能进行预测，优化橡胶和极性小分子配比，同时根据计算结果进行实验验证，得到氢键网络微观结构与宏观物性参数的定量关系，总结出含氢键网络的橡胶基有机杂化阻尼材料的制备规律，达到对材料进行优化设计的目的，为橡胶基阻尼材料的制备提供理论基础，形成一套从模拟计算到优化材料制备过程的新方法。

采用分子模拟和实验相结合的方法对橡胶基有机杂化阻尼材料的氢键网络进行了详细的描述，并建立起氢键网络结构与阻尼性能间的量化关系。研究主要包含以下两个方面：1 橡胶基有机杂化阻尼材料氢键网络结构的分子模拟和测试剖析。采用分子动力学模拟方法从分子层面上研究了不同类型、不同配比的受阻酚/极性橡胶体系的氢键类型、形成过程和数量多寡等特征，并以多种微观结构测试分析方法如红外、核磁等定性表征分析了相关体系的氢键结构；2 氢键网络结构与阻尼性能的定量关系研究。采用线性相关分析等数学方法，分析了分子间氢键数量、自由体积分数和结合能与阻尼参数之间的定量关系，建立了以分子间氢键数量和结合能为自变量的多元线性拟合方程，可预测受阻酚/极性橡胶体系阻尼性能并与实验结果有很好吻合；采用量子力学（QM）计算出受阻酚/极性橡胶体系分子间氢键解离反应的热力学参数，结合分子动力学模拟实验结果得到了分子间氢键解离反应热力学参数与阻尼性能之间的定量关系。这项工作可帮助我们更好地理解极性小分子/聚合物体系的结构-性能关系，为高阻尼材料的筛选和设计提供新的思路和方法。