Polyurethane (PU) has been commonly used in a wide range of applications due to its high flexibility and good UV resistance. Attempts have been extensively carried out to improve the corrosion resistance and mechanical properties of this coating through inclusion of nanomaterials. In this study the graphene oxide nanosheets, covalently functionalized by (3-glycidyloxypropyl) trimethoxysilane, were introduced into the PU matrix to enhance the mentioned weaknesses. The modified (fGO) and unmodified-graphene oxide nanosheets (GO) were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis, field emission-scanning electron microscopy (FE-SEM), UV–vis and thermal gravimetric analysis (TGA). The physical–mechanical properties of the PU coatings reinforced with GO and fGO nanosheets were characterized by dynamic mechanical thermal analysis (DMTA) and tensile test. The influence of GO and fGO nanosheets on the fractured surface morphology of the PU coating after tensile test was studied by SEM analysis. In addition, the corrosion protection properties of the mild steel panels coated with PU coatings were characterized by salt spray test and electrochemical impedance spectroscopy (EIS). The results affirmed the physical–mechanical and anti-corrosion properties enhancement of the PU coating after incorporation of fGO nanosheets. The tensile stress, energy at break, loss factor and storage modulus values were significantly increased by addition of fGO nanosheets. The fGO stability and dispersion in the PU matrix was improved after modification with (3-glycidyloxypropyl) trimethoxysilane. The interfacial bonds between the polyurethane coating-fGO nanosheets were significantly enhanced. Besides the experiments, theoretical quantum mechanics approaches were utilized to examine the interactions of trimethoxysilane with polyurethane and GO surface.

聚氨酯（PU）由于其高柔韧性和良好的抗紫外线性而已被广泛用于各种应用中。已经尝试通过包含纳米材料来改善该涂层的耐腐蚀性和机械性能。在这项研究中，由（3-环氧丙氧基丙基）三甲氧基硅烷共价官能化的氧化石墨烯纳米片被引入PU基质中，以增强上述缺点。改性的（fGO）和未改性的氧化石墨烯纳米片（GO）的特征在于傅立叶变换红外（FT-IR）光谱，X射线衍射（XRD）分析，场发射扫描电子显微镜（FE-SEM），UV–可见光和热重分析（TGA）。用动态机械热分析（DMTA）和拉伸试验表征了用GO和fGO纳米片增强的PU涂层的物理机械性能。通过SEM分析研究了GO和fGO纳米片对拉伸试验后PU涂层断裂表面形态的影响。此外，通过盐雾试验和电化学阻抗谱（EIS）表征了涂有PU涂层的低碳钢板的防腐性能。结果证实，掺入fGO纳米片后，PU涂层的物理，机械和抗腐蚀性能得到了增强。通过添加fGO纳米片，拉伸应力，断裂能，损耗因子和储能模量值显着增加。用（3-环氧丙氧基丙基）三甲氧基硅烷改性后，改善了fGO的稳定性和在PU基质中的分散性。聚氨酯涂层-fGO纳米片之间的界面键显着增强。除了实验，理论量子力学方法被用来检查三甲氧基硅烷与聚氨酯和GO表面的相互作用。