Study on the effect of ultrasonication time on transport properties of polyurethane/organoclay nanocomposite coatings

Abstract

In this study, a series of polyurethane (PU)/ organically modified montmorillonite (OMMT) clay nanocomposites were synthesized by in situ polymerization technique through an ultrasonication-assisted process at various processing times. Wide angle X-ray diffraction (WAXD) was employed to investigate the effect of processing time on degree of delamination of clay platelets. In order to evaluate the effect of ultrasonication time on transport properties of the PU/OMMT composites, diffusion coefficient and maximum water uptake were determined through a water permeation test. Electrochemical impedance spectroscopy (EIS) was carried out to analyze the barrier properties and to evaluate the corrosion performance of these composite coatings on carbon steel panels. It was found that by increasing sonication time, the barrier property of nanocomposites against diffusion of water molecules was improved. This is due to further separation of clay platelets and enhancement of the traveling pathways for water molecules.

Synthesis and characterization of polyurethane–organoclay nanocomposites based on renewable castor oil polyols

“…The sonication assisted in breaking the clay aggregate [51] into dispersed clay particles. High shear homogenization is beneficial for dispersing the clay platelets homogeneously [52] throughout the polymer matrix.…”

Linseed oil polyol/ZnO bionanocomposite towards mechanically robust, thermally stable, hydrophobic coatings: a novel synergistic approach utilising a sustainable resource

“…The R p value for the LPP/ZnO-0.06 coated CS showed a very high (4.46 Â 10 5 kU, 1.58 Â 10 2 kU) increase with respect to the LPP coated CS (68.94 kU, 18.53 kU) in 3.5 wt% NaCl and 3.5 wt% HCl, respectively. 18,77 The hydrophobic character of the virgin coatings increases with the incorporation of ZnO NP (as discussed in previous section), which do not allow wetting of the surface that inhibits penetration of corrosive ions. These results demonstrate the ability of the nanocomposite coatings to inhibit the corrosion process by blocking Scheme 5 The mechanism occurring at the -COOH end of LPP.…”

“…The overall underlying idea is to harness nature's abundant sustainable resources, by combination of the "green" characteristics of biopolymers and the high performance rendered by nanomaterials for advanced functional applications such as drug delivery, medicine, sensing devices, ame retardancy, food packaging, gasdiffusion barriers, protective coatings and others. The inclusion of such nanoparticles overcomes some drawbacks of plant oil derivatives such as poor load bearing ability, hardness, inadequate rigidity and strength, 2,11,13 and improves the antimicrobial behavior, [14][15][16] thermal stability, 7,11,16 corrosion protection performance 17,18 and other properties, in nal BNCs thus broadening their areas of applications. Their derivatives such as alkyds, polyesteramides, polyurethanes [PU] and others nd applications as biodiesel, printing inks, lubricants, adhesives, coatings and paints.…”

“…1,2 Plant oils are nature's most abundantly available, cost effective, non-toxic and environmentally friendly bioresources. 18 Raju et al developed hydrophobic CO PU/urea-silica hybrid coatings by introducing hydrolyzable -Si-OCH 3 groups using 3-glycidoxypropyltrimethoxy silane by chemical reaction. [3][4][5] BNCs from plant oil derivatives have been obtained with nanosized reinforcements such as nano-clays, 6 nano-metal/metal oxides, 7 graphene, 8,9 carbon nanotubes, 10 fumed silica, 11 conducting polymers 12 and others.…”

Barrier Coating for Flexible Display with Intercalated Nanoclay Composite

“…High aspect ratio of nanoclay was proved to improve the barrier properties [13][14][15], because it might attribute the reduction in straightway movement of water vapor and oxygen molecule, which results in increasing the effective paths for diffusion of each molecule [16]. Several reports have shown that the dispersion of nanoclay and the morphology of the nanocomposite depend on various factors, such as the mixing method [17], mixing speed [18], and clay content [19].…”