Cong Chuanbo, Peng Daigang, Liu Qingkun, Yuan Mingyang, Meng Xiaoyu, Zhou Qiong
New Energy and Material College, China University of Petroleum, Beijing 102249, China.
Polymers (Basel). 2023 Oct 19;15(20):4151. doi: 10.3390/polym15204151.
This work aimed to investigate the CO gas barrier and mechanical properties of fluorine rubber nanocomposites filled with Ca/Al layered hydroxide (graphene oxide [GO]/LDH-CaAl) modified by GO. GO/LDH-CaAl nanocomposite fillers were prepared by depositing Ca/Al layered hydroxide (LDH-CaAl) into the surface of alkalized GO (Al-GO). The prepared GO/LDH-CaAl nanocomposite fillers and complexes were characterized by Fourier infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) for structural and micromorphological characterization. The results showed that GO/LDH-CaAl was successfully prepared with strong interactions between Al-GO and LDH, and the compatibility of GO/LDH-CaAl nanocomposite fillers with the polymer was significantly improved compared with that of LDH-CaAl. Consequently, both the fracture strength () and strain () of GO/LDH-CaAl nanocomplexes remarkably increased, and they exhibited excellent mechanical properties. Differential scanning calorimetry and thermogravimetric analysis were used to characterize the thermal stability of GO/LDH-CaAl nanocomposite fillers, and GO/LDH-CaAl nanocomposite fillers have better thermal stability than LDH-CaAl. The reaction products (S-LDH-CaAl and S-GO-CaAl) of LDH-CaAl and GO/LDH-CaAl with CO were characterized using XRD and TGA, respectively, and the results show that LDH-CaAl reacts readily and chemically with CO, resulting in a lower diffusion coefficient of CO in the LDH-CaAl nanocomplexes than that of the GO/LDH-CaAl nanocomplexes and leading to the destruction of the laminar structure of LDH-CaAl, while GO/LDH-CaAl has better CO resistance stability. GO/LDH-CaAl nanocomplexes exhibited a reduced content of hydroxyl groups with pro-CO nature exposed on the surface of LDH-CaAl, improving the interfacial interaction between the nanofillers and the rubber matrix and enhancing the dispersion of GO/LDH-CaAl in the polymers. Moreover, CO in the soluble GO/LDH-CaAl nanocomposites was significantly reduced, while the diffusion properties demonstrated weak temperature dependence on solubility. The mechanism of the CO gas barrier of polymers filled with GO/LDH-CaAl was proposed on the basis of the Arrhenius equation.
本研究旨在探究填充有经氧化石墨烯（GO）改性的钙铝层状氢氧化物（氧化石墨烯[GO]/层状双氢氧化物-LDH-CaAl）的氟橡胶纳米复合材料的一氧化碳气体阻隔性能和力学性能。通过将钙铝层状氢氧化物（LDH-CaAl）沉积到碱化的GO（Al-GO）表面制备了GO/LDH-CaAl纳米复合填料。采用傅里叶红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对制备的GO/LDH-CaAl纳米复合填料及其复合物进行结构和微观形貌表征。结果表明，成功制备了GO/LDH-CaAl，Al-GO与LDH之间存在强相互作用，与LDH-CaAl相比，GO/LDH-CaAl纳米复合填料与聚合物的相容性显著提高。因此，GO/LDH-CaAl纳米复合物的断裂强度（）和应变（）均显著增加，且表现出优异的力学性能。采用差示扫描量热法和热重分析法对GO/LDH-CaAl纳米复合填料的热稳定性进行表征，结果表明GO/LDH-CaAl纳米复合填料比LDH-CaAl具有更好的热稳定性。分别利用XRD和TGA对LDH-CaAl以及GO/LDH-CaAl与CO的反应产物（S-LDH-CaAl和S-GO-CaAl）进行表征，结果表明LDH-CaAl与CO易于发生化学反应，导致CO在LDH-CaAl纳米复合物中的扩散系数低于GO/LDH-CaAl纳米复合物，且导致LDH-CaAl层状结构遭到破坏，而GO/LDH-CaAl具有更好的抗CO稳定性。GO/LDH-CaAl纳米复合物表面具有亲CO性质的羟基含量降低，改善了纳米填料与橡胶基体之间的界面相互作用，增强了GO/LDH-CaAl在聚合物中的分散性。此外，可溶性GO/LDH-CaAl纳米复合材料中的CO显著减少，且扩散性能对溶解度的温度依赖性较弱。基于阿伦尼乌斯方程提出了填充GO/LDH-CaAl的聚合物的CO气体阻隔机理。
