In this paper, waterborne epoxy (EP) coatings were modified by the incorporation of synthetic structure (DA/meso-TiO2) to improve the anticorrosion ability of waterborne epoxy coatings for steel structures. Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption–desorption, X-ray diffraction (XRD) and thermo-gravimetric analyses (TGA) were used to characterize textural properties of DA/meso-TiO2. Corrosion performances of mild carbon steel coated samples were tested by salt spray tests and employing electrochemical impedance spectroscopy (EIS). FTIR, XRD, TGA and nitrogen adsorption–desorption attested to dopamine polymerization within the mesopores and on the surface of meso-TiO2. The results of EIS and salt spray test showed that the specimen coated with 1.0 wt % DA/meso-TiO2 exhibited optimum corrosion performance among other coating specimens.
In this study, the preparation of modified graphene oxide (GO) synergistic structure (ZSM-5-NH-GO) and the effect of this structure on the corrosion performance of epoxy coatings were investigated. The structural and morphological properties of ZSM-5-NH-GO were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The corrosion performances were studied by electrochemical impedance spectroscopy (EIS) and salt spray tests. The EIS results showed that the corrosion resistance of steel substrate was considerably improved by ZSM-5-NH-GO. The salt spray tests demonstrated that the ZSM-5-NH-GO coating provided strong corrosion performance for steel substrate. The mechanical properties of the epoxy-composite coatings containing ZSM-5-NH-GO were studied by adhesion tests. The above results indicated that the composite coating containing 0.7 wt % ZSM-5-NH-GO composite possessed most excellent anti-corrosion performance compared with other epoxy coatings.
Aiming to improve the flame retardancy performance of natural rubber (NR), we developed a novel flame retardant synergistic agent through grafting of MCM-41 to graphene oxide (GO), named as GO-NH-MCM-41, as an assistant to intumescent flame retardants (IFR). The flame retardancy of NR/IFR/GO-NH-MCM-41 composites was evaluated by limited oxygen index (LOI), UL-94, and cone calorimeter test. The LOI value of NR/IFR/GO-NH-MCM-41 reached 26.3%; the UL-94 ratings improved to a V-0 rating. Moreover, the addition of GO-NH-MCM-41 decreased the peak heat release rate (PHRR) and the total heat release (THR) of the natural rubber composites. Furthermore, the addition of GO-NH-MCM-41 increased the thickness of char residue. The images of SEM indicated the char residue was more compact and continuous. The degradation of GO-NH-MCM-41-based NR composites was completed with a mass loss of 35.57% at 600 °C. The tensile strength and the elongation at break of the NR/IFR/GO-NH-MCM-41 composites were 13.9 MPa and 496.7%, respectively. The results of the rubber process analyzer (RPA) reached the maximum value, probably due to a better network of fillers in the matrix.
In this paper, phosphated K-carrageenan (P-KC) was obtained by reacting POCl3 with the renewable source K-carrageenan (KC). P-KC and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) were added into waterborne epoxy (EP) to improve its flame retardancy. The structure of P-KC was studied comprehensively using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), showing the successful synthesis of P-KC. The flame retardancy of the EP was evaluated by the cone calorimeter test. The results showed that different mass ratios of DOPO and P-KC affected the flame retardancy of EP. When the mass ratio of DOPO and P-KC was 2:1, total heat release (THR) and total smoke production (TSP) decreased by 48.7% and 37.4%, respectively. The microstructures of residue char were observed by FTIR and scanning electron microscopy (SEM), indicating that the flame-retardant waterborne epoxy (FR-EP) system held a more cohesive and denser char structure. The char inhibited the diffusion of heat and oxygen, which played a key role in the flame retardancy.