Development of Metallo (Calcium/Magnesium) Polyurethane Nanocomposites for Anti-Corrosive Applications

Abstract

Long-term corrosion protection of metals might be provided by nanocomposite coatings having synergistic qualities. In this perspective, rapeseed oil-based polyurethane (ROPU) and nanocomposites with calcium and magnesium ions were designed. The structure of these nanocomposites was established through Fourier-transform infrared spectroscopy (FT-IR). The morphological studies were carried out using scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM). Their thermal characteristics were studied using thermogravimetric analysis (TGA). Electrochemical experiments were applied for the assessment of the corrosion inhibition performance of these coatings in 3.5 wt. % NaCl solution for 7 days. After completion of the test, the results revealed a very low icorr value of 7.73 × 10−10 A cm−2, a low corrosion rate of 8.342 × 10−5 mpy, impedance 1.0 × 107 Ω cm2, and phase angle (approx 90°). These findings demonstrated that nanocomposite coatings outperformed ordinary ROPU and other published methods in terms of anticorrosive activity. The excellent anti-corrosive characteristic of the suggested nanocomposite coatings opens up new possibilities for the creation of advanced high-performance coatings for a variety of metal industries.

Mn(II)‐ and Zn(II)‐ Based Nanocomposites Metallopolymer for Corrosion Protective Coatings

“…The appearance of these peaks and the disappearance of peak at 1052–1053 (terminal hydroxyl), are related to the formation of urethane through the reaction terminal hydroxyl groups of Mn‐TGFA/Zn‐TGFA with isocyanate group of TDI [34] . The spectra of these two resins (Mn 5 NMP 35 /Zn 5 NMP 35 ) also show the peaks for the − C (= O )−O−Mn/Zn (1730–1729 cm −1 ) and −O−Mn/Zn−O− linkages (768 cm −1 and 607–610 cm −1 ) as compared to virgin CO based polyurethane [34] . It is observed in the spectra of Mn 5 NMP 35 (e) and Zn 5 NMP 35 (f) coatings that the disappearance of the peak at 2272, which related to the free −NCO.…”

“…FTIR spectra of Mn 5 NMP 35 (c), and Zn 5 NMP 35 (d) uncured resins reveal the characteristic peaks as compared to FTIR spectra of the respective monomers at 1712–1713 (urethane carbonyl stretching), 1070–1071 (C−O−C stretching), 1222–1228 (C(=O)−O urethane), 3289–3290 (−NH of urethane overlap with free hydroxyl), 2272 (free −NCO, sharp peak). The appearance of these peaks and the disappearance of peak at 1052–1053 (terminal hydroxyl), are related to the formation of urethane through the reaction terminal hydroxyl groups of Mn‐TGFA/Zn‐TGFA with isocyanate group of TDI [34] . The spectra of these two resins (Mn 5 NMP 35 /Zn 5 NMP 35 ) also show the peaks for the − C (= O )−O−Mn/Zn (1730–1729 cm −1 ) and −O−Mn/Zn−O− linkages (768 cm −1 and 607–610 cm −1 ) as compared to virgin CO based polyurethane [34] .…”

“…[34] The spectra of these two resins (Mn 5 NMP 35 / Zn 5 NMP 35 ) also show the peaks for the À C(=O)À OÀ Mn/Zn (1730-1729 cm À 1 ) and À OÀ Mn/ZnÀ OÀ linkages (768 cm À 1 and 607-610 cm À 1 ) as compared to virgin CO based polyurethane. [34] It is observed in the spectra of Mn 5 NMP 35 (e) and Zn 5 NMP 35 (f) coatings that the disappearance of the peak at 2272, which related to the free À NCO. In addition to this, shifting of peaks are also observed like peak of À NH of urethane observed at 3416-3423 cm À 1 instead of the peak of uncured resin at 3289-3290 cm À 1 .…”

“…FTIR spectral technique was used to establish the structure of the formulated Mn 5 NMP 35 and Zn 5 NMP 35 by comparing these spectra with their respective ligand's spectra (spectra of virgin monomer and metal containing monomer). [34] Figure 1 shows the FTIR spectra of Mn 5 -TGFA(a), and Zn 5 -TGFA(b) along with Mn 5 NMP 35 (c) and Zn 5 NMP 35 (d) uncured resins. Figure 1 also shows the spectra of Mn 5 NMP 35 (e) and Zn 5 NMP 35 (f) cured resins or coatings.…”

Failure Analysis of Abnormal Cracking of the Track Circuit Reader Antenna Baffle for High-Speed Trains

“…Due to its high hardness, good strength, high elasticity, wear resistance, tear resistance, and aging resistance [ 1 , 2 ], PUR is widely used [ 3 , 4 , 5 , 6 ]. However, it turns out that like other polymer materials [ 7 ], PUR also has its drawbacks.…”