基于受阻酚悬挂链的超分子网络阻尼材料结构构筑及阻尼机理研究

The introduce of dynamic intermolecular hydrogen bonds between hindered phenol and polymer to enhance energy dissipation could effectively improve the limited damping capacity of traditional damping materials. However, because of the instability and narrow damping temperature range caused by the strong relaxation of hindered phenol, the application of the material was limited. To solve this problem, the hindered phenol based hung-chain structure was first constructed in this article. By combining molecular dynamics simulation and experiment results, the quantitative relationship between the composition as well as structure and the microstructure as well as damping properties of the hung-chain was established. Moreover, in order to prepare “non-chemical crosslinking, high damping, wide temperature range” damping material, a double polymer supramolecular network structure with hindered phenol hung-chain as linking element was further designed based on the conclusions above. And the relationship between the structure and damping properties of the supramolecular network was then clarified by the use of two-dimensional correlation infrared analysis. Therefore, the research results would provide important theoretical basis and technical support for the design and preparation of “high damping, wide temperature range” thermoplastic damping materials.

利用受阻酚与聚合物间动态氢键相互作用增强能量耗散可有效改善传统阻尼材料阻尼上限不足的缺陷，然而受阻酚松弛运动较强导致的不稳定性及阻尼温域窄的问题却限制了该类材料的应用。针对这一情况，本项目拟通过构筑受阻酚基悬挂链结构，同步改善材料稳定性及阻尼温域。结合分子动力学模拟，建立悬挂链组成、结构与微观形貌、阻尼性能间的定量关系，揭示相应阻尼机理。在此基础上，进一步从分子层面设计以受阻酚悬挂链为链接基元的双聚合物超分子网络结构，以实现“非化学交联、高阻尼、宽温域”阻尼材料的制备。并结合二维相关红外分析，阐明超分子网络结构与阻尼性能间的相互关系。为设计和制备“高阻尼、宽温域”热塑性阻尼材料提供理论指导。

利用受阻酚与聚合物间动态氢键相互作用增强能量耗散可有效改善传统阻尼材料阻尼上限不足的缺陷，然而受阻酚松弛运动较强导致的不稳定性及阻尼温域窄的问题却限制了该类材料的应用。本项目以受阻酚链极性和链长为变量，通过分子设计构筑不同结构受阻酚，并与聚氨酯(TPU)复配制备杂化材料。采用分子动力学模拟方法计算了杂化体系氢键强度、氢键浓度、结合能、相对自由体积(FFV)、分子链回转半径(Rg)及分子链相对浓度变化，结合X射线衍射及动态力学性能分析(DMA)等实验表征方法，揭示了受阻酚结构变化与微观形貌、稳定性及阻尼性能间关系。相较于受阻酚极性，改变其链长对微观形貌及阻尼性能影响规律性强，更利于推广应用。受阻酚链长增加，其微观形貌由结晶态向非晶态转变；杂化体系稳定性及阻尼性能受受阻酚分子内氢键调控，长链受阻酚杂化体系中受阻酚分子内氢键消失，体系可同步实现“高稳定性、高阻尼性”。基于分子内氢键调控理念，进一步构筑受阻酚/TPU-聚醋酸乙烯酯(PVAc)交替多层层状体系，采用分子动力学模拟方法计算了层状体系分子链相对浓度、Rg、氢键数目、氢键浓度、结合能及FFV变化，结合扫描电子显微镜及DMA等实验表征方法，阐明了受阻酚含量变化及层状体系层数变化与稳定性及阻尼性能间关系。交替多层结构可实现受阻酚向层界面的定向迁移，一方面减弱或消除了受阻酚分子内氢键，提高体系稳定性，另一方面实现了以受阻酚为链接基元的双聚合物超分子网络结构构筑，提高体系阻尼性能。高受阻酚含量、高层数层状体系可实现“高稳定性、高阻尼、宽温域”阻尼材料制备。综上，本研究为设计和制备“高阻尼、宽温域”热塑性阻尼材料提供理论及技术支撑。