Authors: Chuanbo Cong | Daigang Peng | Qingkun Liu | Mingyang Yuan | Xiaoyu Meng | Qiong Zhou
Source: Polymers (article, 2023-10-19)
Field: Materials Science — Materials Chemistry

Effect of Graphene Oxide-Modified CaAl-Layered Double Hydroxides on the Carbon Dioxide Permeation Properties of Fluoroelastomers This work aimed to investigate the CO<sub>2</sub> gas barrier and mechanical properties of fluorine rubber nanocomposites filled with Ca/Al layered hydroxide (graphene oxide [GO]/LDH-Ca<sub>2</sub>Al) modified by GO. GO/LDH-Ca<sub>2</sub>Al nanocomposite fillers were prepared by depositing Ca/Al layered hydroxide (LDH-Ca<sub>2</sub>Al) into the surface of alkalized GO (Al-GO). The prepared GO/LDH-Ca<sub>2</sub>Al 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-Ca<sub>2</sub>Al was successfully prepared with strong interactions between Al-GO and LDH, and the compatibility of GO/LDH-Ca<sub>2</sub>Al nanocomposite fillers with the polymer was significantly improved compared with that of LDH-Ca<sub>2</sub>Al. Consequently, both the fracture strength (<i>σ<sub>b</sub></i>) and strain (<i>ε<sub>b</sub></i>) of GO/LDH-Ca<sub>2</sub>Al 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-Ca<sub>2</sub>Al nanocomposite fillers, and GO/LDH-Ca<sub>2</sub>Al nanocomposite fillers have better thermal stability than LDH-Ca<sub>2</sub>Al. The reaction products (S-LDH-Ca<sub>2</sub>Al and S-GO-Ca<sub>2</sub>Al) of LDH-Ca<sub>2</sub>Al and GO/LDH-Ca<sub>2</sub>Al with CO<sub>2</sub> were characterized using XRD and TGA, respectively, and the results show that LDH-Ca<sub>2</sub>Al reacts readily and chemically with CO<sub>2</sub>, resulting in a lower diffusion coefficient of CO<sub>2</sub> in the LDH-Ca<sub>2</sub>Al nanocomplexes than that of the GO/LDH-Ca<sub>2</sub>Al nanocomplexes and leading to the destruction of the laminar structure of LDH-Ca<sub>2</sub>Al, while GO/LDH-Ca<sub>2</sub>Al has better CO<sub>2</sub> resistance stability. GO/LDH-Ca<sub>2</sub>Al nanocomplexes exhibited a reduced content of hydroxyl groups with pro-CO<sub>2</sub> nature exposed on the surface of LDH-Ca<sub>2</sub>Al, improving the interfacial interaction between the nanofillers and the rubber matrix and enhancing the dispersion of GO/LDH-Ca<sub>2</sub>Al in the polymers. Moreover, CO<sub>2</sub> in the soluble GO/LDH-Ca<sub>2</sub>Al nanocomposites was significantly reduced, while the diffusion properties demonstrated weak temperature dependence on solubility. The mechanism of the CO<sub>2</sub> gas barrier of polymers filled with GO/LDH-Ca<sub>2</sub>Al was proposed on the basis of the Arrhenius equation. Nanocomposite ; Thermogravimetric analysis ; Hydroxide ; Layered double hydroxides ; Materials science ; Graphene ; Differential scanning calorimetry ; Thermal stability ; Oxide ; Fourier transform infrared spectroscopy ; Chemical engineering ; Scanning electron microscope ; Intercalation (chemistry) ; Exfoliation joint ; Nuclear chemistry ; Composite material ; Chemistry ; Inorganic chemistry ; Nanotechnology Layered Double Hydroxides Synthesis and Applications ; Polymer Nanocomposites and Properties ; Polymer Nanocomposite Synthesis and Irradiation