水力机械耐磨蚀聚氨酯/石墨烯纳米涂层研制及性能研究

Sediment erosion greatly affects the service life and efficiency of hydraulic machinery in sediment-laden rivers, which causes safety problems in serious cases and has become a critical issue badly needed to be solved in hydraulic and hydro-Power Engineering. In this project, polyurethane nanocomposite coating will be prepared by blending modified graphene, a novel interfacial adhesive and polyurethane for protecting metal surface. The destruction form and morphology of coating will be observed by x-ray diffractometer and scanning electron microscope under different abrasion conditions, such as the amount of interface adhesive, coating thickness, flow rate, sediment properties. The relationship between the failure of polyurethane nanocomposite coating and the influence factors will be discussed deeply, in order to obtain the abrasion law of polyurethane/graphene nanocomposite coating. The influence of internal and external factors on interfacial bonding and abrasion law will be studied, such as material chemical structure, composition, and flow rate, sediment characteristics. Finally, a feasible scheme to improve the wear resistance of polyurethane nanocomposite coating will be suggested, which will provide theoretical basis and experimental evidence for polyurethane nanocomposite coating design and application.

水力机械在多泥沙河流磨蚀问题严重，极大影响其使用寿命和工作效率，对安全生产造成隐患，泥沙磨蚀成为水利水电生产中亟待解决的难题之一。本项目拟采用表面功能化石墨烯、新型界面粘接材料和聚氨酯制备出聚氨酯纳米涂层以抵御金属表面的磨蚀。将以界面粘接材料用量、涂层厚度、水流冲磨速度、泥沙含量、泥沙粒度等作为研究参数，系统讨论涂层物性、冲磨条件对涂层破坏形貌及形式的影响，深入研究聚氨酯纳米涂层失效与各参数之间的影响规律。综合分析材料化学结构、组成等内在因素对石墨烯与聚氨酯界面粘接、聚氨酯纳米复合材料与金属界面粘接的影响，以及水流速度、泥沙特性等外在因素对聚氨酯纳米涂层耐磨蚀性能的影响，提出改善水力机械耐磨性能的可行性方案，为聚氨酯耐磨涂层的设计及应用提供理论基础和试验依据。

泥沙磨蚀对水力机械的寿命和工作效率影响极大，已成为水利水电生产中亟待解决的难题之一。高分子耐磨材料由于具有显著的抗空蚀性、经济性，在水利水电工程磨蚀防护领域的研究及应用倍受关注。本课题采用十八胺（ODA）、甲苯-2,4-二异氰酸酯（TDI）对石墨烯表面改性，改性后的石墨烯与聚氨酯以一定比例通过三辊机混合，高温固化制备出聚氨酯/石墨烯纳米复合材料。研究了复合材料力学性能、耐磨性能、耐水性能等；研究了聚氨酯涂层的粘接性能，对不同粘接剂在聚氨酯与金属之间的粘接进行评估，分析了粘接剂的耐水性能；探讨了聚氨酯/石墨烯纳米涂层耐磨蚀机理。试验结果表明ODA、TDI与石墨烯的活性官能团之间发生了化学反应，改性后的石墨烯的分散性能得到改善；表面改性石墨烯与聚氨酯复合后改善了聚氨酯的力学性能、耐磨性能和耐水性能。当加入0.06wt%的GO-TDI时，复合材料的拉伸强度达到47.3MPa，比纯聚氨酯提高了91.4%；此时复合材料的质量损失量、累计体积损失量最小，经过168h水浸后，复合材料的拉伸强度、断裂伸长率分别达到48.4MPa、1458.6%，较纯聚氨酯水浸后分别高了2.33%、0.71%；聚氨酯-金属界面粘接所用的粘接剂A性能最好，粘接强度达到101.76kN/m。同时粘接剂A的耐水性能最优，经过168h浸泡粘接性能仅下降9.6%；石墨烯加入能够起到“润滑剂”的角色，降低磨损，同时由于其较高的强度，提高涂层的耐磨性。石墨烯的加入可更多的吸收能量及缓冲作用力，起到抗空蚀的作用。根据试验结果分析提出改善聚氨酯纳米涂层耐磨性能的可行性方案，并进行了现场试验，效果良好。通过对聚氨酯/石墨烯复合材料的研究，提出可行性方案并加以应用，本项目的开展可为水力机械磨蚀防护研究提供基础数据和研究依据。