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Although epoxy resin has been extensively used in the field of wind turbine blades, polyurethane has attracted much attention in recent years, due to its potential value of better fatigue resistance, lower processing viscosity and higher strength than epoxy resin blades. Herein, we construct a dense cross-linking structure in polyurethane (PU) based on different amounts of hydroxypropyl methacrylate (HPMA) with low processing viscosity and excellent mechanical properties. By increasing the content of HPMA, the thermal stability of PU is enhanced, but the micro-morphology does not change significantly. When the content of HPMA is 50 g (in 200 g copolymer), the PU sample PH-50 exhibits a viscosity of 70 MPa·s and a gelation time of 120 min at 25 °C, which is sufficient to complete processes like pouring and filling. By post-curing the PH-50 at 80 °C for 2 h, the heat distortion temperature can reach 72 °C, indicating the increase of temperature resistance. The PU copolymers also have excellent mechanical and dynamic thermo-mechanical properties due to the cross-linking structure between PU chains and poly-HPMA chains. Additionally, the PU copolymer has excellent compatibility with various glass fiber fabrics (GFF), showing a good match in the vacuum infusion experiment and great properties in the mechanical test. By compounding PH-50 with GFF, the composite with high strength is easily prepared for a wind turbine blade in various positions. The tensile strengths of the composites are all over 1000 MPa in the 0° direction. Such composites are promising for the future development of wind turbine blades that meet the stringent requirements for outstanding processing and mechanical properties. [ABSTRACT FROM AUTHOR]

In this paper, citric acid was used as carbon source, diethylenetriamine and urotropine were used as precursors, and N-doped carbon dots (cdh-CDs) with luminescent properties were synthesized by microwave method. The structure of the sample was analyzed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffractometry (XRD), ultraviolet spectrophotometer (UV), fluorescence spectroscopy, etc., and it was proved that cdh-CDs with an amorphous structure about 4–10 nm in diameter was synthesized. The corrosion inhibition performance of cdh-CDs in 1 M hydrochloric acid was evaluated by static weight loss and electrochemical method. The results showed that cdh-CDs have a good corrosion inhibition performance at 60°C, the inhibition efficiency can reach 81.2% when the dosage is 600 ppm. Electrochemical results showed that cdh-CDs are mixed inhibitors which mainly inhibit cathodes. [ABSTRACT FROM AUTHOR]

In this paper, a Schiff base (SB-1) and derivatives (SB-2 and SB-3) was synthesized and characterized by IR and 1H NMR methods, the corrosion efficiency and mechanism of carbon steel in 1: 1 hydrochloric acid was obtained by weight loss measurements, atomic absorption spectrophotometry, electrochemical measurements, atomic force microscopy studies and quantum chemical calculations. The results indicated that the inhibition efficiency was SB-3 > SB-2 > SB-1 at low concentration of inhibitors. Under high concentration, they have same efficiency. The electrochemical measurements showed that the synthesized compounds is an efficient mix-type inhibitors and its efficiency increased with the increase in inhibitor concentrations. The quantum chemical parameters were calculated using the density functional theory (DFT), and results showed that the inhibitor and the metal surface interacted with the donor-acceptor to achieve the effect of corrosion inhibition. [ABSTRACT FROM AUTHOR]

• The graft copolymer of β-cyclodextrin was applied to oil field. • Applying the β-cyclodextrin to a corrosion and scale inhibitor system. • The inhibitor was evaluated by a new atomic absorption spectrophotometry. • Analysis of the structure of salt water corrosion products. In this paper, polyaspartic acid graft copolymer (PASP/β-CD) was synthesized by β-cyclodextrin intermediate and polysuccinimide (PSI). The corrosion inhibition efficiency of PASP/β-CD on N80 carbon steel in brine were evaluated by weight loss measurements, electrochemical methods, atomic absorption spectrophotometry (AAS), surface analysis (SEM and EDS) and corrosion products analysis (XRD). The results showed that the PASP/β-CD was a mixed-type corrosion inhibitor. At 60℃, the corrosion inhibition efficiency in simulated oilfield water reached 68.4% at 800 mg/L. [ABSTRACT FROM AUTHOR]

Inspired by the high-water solubility, photoluminescence and low cytotoxicity of N-doped carbon quantum dots (N-CQDs), fluorescent corrosion inhibitors with size of 4–8 nm were synthesized from disodium ethylenediaminetetraacetate, sulfamic acid, and urotropine salt. We expect that these N-CQDs may possess an excellent protective ability to inhibit the corrosion of carbon steel in aggressive solutions owing to its special functional group. The inhibitory mechanism of the inhibitor on N80 steel in saturated CO2 3 wt % NaCl solution was studied by weight loss, adsorption curve fitting, electrochemical measurement, and surface morphology and elemental analysis. The results show that corrosion of N80 carbon steel in saturated CO2 3 wt % NaCl solution is significantly inhibited by the addition of N-CQDs, which is attributed to the formation of its adsorption film, preventing the contact of iron with chloride ions and is an effective corrosion inhibitor. [ABSTRACT FROM AUTHOR]

• A new functional inhibitor N-CD S was synthesized by microwave method. • The N-CDs could act as effective corrosion inhibitor for the N80 steel, and the inhibition efficiency in 1 M HCl and CO 2 -saturated 3.5 wt% NaCl solutions at 70 °C reached up to 91.5% and 94.6% at 200 mg/L of N-CDs, respectively • N-CDs particles can form a hydrophobic protective layer on the surface of carbon steel through physical and chemical adsorption to prevent corrosion In this work, the eco-friendly of functionalized carbon dots (N-CDs) was synthesized by the microwave method. The corrosion inhibition behavior of N-CDs for N80 steel in 1 M HCl and CO 2 -saturated 3.5 wt% NaCl solutions were systematically investigated by weight loss, electrochemical measurements and surface morphology. The results revealed that N-CDs exhibited outstanding inhibitory performance. The inhibitory efficiency in 1 M HCl and CO 2 -saturated 3.5 wt% NaCl solution at 70 °C reached 89.04% and 94.6% at 200 mg/L of N-CDs, respectively. Meanwhile, N-CDs was a mixed inhibitor that mainly suppressed the cathode in corrosion conditions (1 M HCl), while it was a mixed inhibitor that primarily inhibited the anode in the saline solution. In addition, based on the analysis and mechanism study of the surface of N80 steel, N-CDs followed the Langmuir adsorption isotherm and adsorbed on the metal surface through physical and chemical adsorption to inhibit corrosion, which fully explained the inhibition mechanism of N-CDs at metal/solution interface. Therefore, this work could provide new ideas for exploring efficient and environmentally friendly corrosion inhibitors. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, a corrosion inhibitor containing nitrogen atoms and a conjugated π bond was synthesised, and its final product synthesised by the optimal conditions of the orthogonal test results is named multi-mannich base (MBT). The corrosion inhibition effect on the N80 steel sheet of the corrosion inhibitor was evaluated in a CO2 saturated solution containing 3 wt % NaCl; the corrosion rate was 0.0446 mm/a and the corrosion inhibition rate was 90.4%. Through electrochemical and adsorption theory study, MBT is a mixed corrosion inhibitor that mainly shows cathode suppression capacity. The adsorption of MBT on the surface of the steel sheet follows the Langmuir adsorption isotherm; it can be spontaneously adsorbed on the surface of the N80 steel sheet, which has a good corrosion inhibition effect. The surface of the N80 steel sheet was microscopically characterised by atomic force microscope (AFM). It can be seen from the results that the N80 steel sheet with MBT added is significantly different from the blank control group; the surface of the steel sheet is relatively smooth, indicating that MBT forms an effective protective film on the surface of N80 steel, which inhibits the steel sheet. [ABSTRACT FROM AUTHOR]