Properties of coatings

L. W. Hill, Mechanical Properties of Coatings, Federation of Societies for Coatings Technology, Philadelphia, Pa., 1987. 

Sulfonic acid salts have found widespread use in the area of corrosion inhibition. Lubrizol Corporation produces a wide variety of sulfonic acids, particularly in the form of magnesium salts, for use in lubricant formulations, anticorrosion coatings, greases, and resins (146,147). Petroleum sulfonates are used in epoxy resin elastomers to improve anticorrosion properties of coatings and sealants (qv) (148,149). 

Brush plating is a special technique which dispenses with a container and uses a swab soaked in electrolyte applied to the work. In jet plating a stream of electrolyte is applied to the cathode. Both are methods of selective plating, applying an electrodeposit to only a part of an article. Little has been published about the techniques or the properties of coatings they produce. 

A number of physical and mechanical properties of coating metals need to be considered when making a choice of metal to be used in a particular application. 

It is possible to calculate a number of different kinds of "effective" crosslink densities. Bauer et al have used a quantity they termed the "elastically effective crosslink density " (Cel) correlate cure with solvent resistance and other physical properties of coatings (7-10). The correlation was basically empirical. Formally, the is a calculation of the number of functional groups attached to the infinite network for which there are at least two other paths out to the network on the given polymer or crosslinker. Thus, chains with only one or two paths to the infinite network are excluded. The following expression can be written for... 

Touyeras F, Hihn JY, Bourgoin X et al (2005) Effects of ultrasonic irradiation on the properties of coatings obtained by electroless plating and electroplating. Ultrason Sonochem 12 13-19... 

Initially, cycling in the coin cells, and later, in full prismatic cells with rated capacity of 7 Ah were used in our investigations. Also, advanced impedance spectroscopy methods were used to evaluate the electrochemical properties of coated materials. 

Table 2 - Stress corrosion cracking properties of coated 7075-T6 A1 alloy from proving ring tests (stress = 40 ksi or 275 MPa).

Mai Y.W. and Castino F. (1985). The debonding and pull-out properties of coated Kevlar fibers from an epoxy resin matrix. J. Mater. Sci. Lett. 4, 505-508. 

Table III PROPERTIES OF COATINGS BASED ON BRASSYLIC ACID AT VARIOUS HMMM LEVELS, BAKED AT 133 °C AND 150 °C ...

Kraemer, S.M. Hering, J.G. (1997) Influence of solution saturation state on the kinetics of ligand-controlled dissolution of oxide phases. Geochim. Cosmochim. Acta 61 2855-2866 Kraemer, S.M., Xu, J., Raymond, K.N. Spo-sito, G. (2002) Adsorption of Pb(II) and Eu(III) by oxide minerals in the presence of natural and synthetic hydroxamate sidero-phores. Environ. Sd. Technol. 36 1287-1291 Kraemer, S.M. Cheah, S.-F. Zapf, R. Xu, J. Raymond, KN. Sposito, G. (1999) Effect of hydroxamate siderophores on Fe release and Pb(II) adsorption by goefhite. Geochim. Cosmochim. Acta 63 3003—3008 Kratohvil, S. Matijevic, E. (1987) Preparation and properties of coated uniform colloidal partides. I. Aluminum (hydrous) oxide on hematite, diromia, and titania. Adv Ceram. Mater. 2 798-803... 

It was found that the competitive adsorption of 1 and AN molecules on the Cd electrode affected the kinetics of the Cd(II) electroreduction [226]. The physicochemical properties of coatings and effects of organic additives on cadmium deposition from iodide-water-AN mixtures were also studied by Kuznetsov et al. [225]. 

Abstract A colloidal solution of titanium dioxide (TiO ) nanoparticles was prepared by the solvothermal method and dip-coated onto a polypropylene fabric with TMOS binder. The prepared TiO particles, colloidal solution and the coated fabrics were characterized by X-ray diffraction, SEM and TEM. The results showed that the TiO particles prepared by the solvothermal method were composed of anatase which uniformly coated the snbstrate. Photocatalysis induced bactericidal properties of coated fabrics were tested by measuring the viability of Escherichia coli. It was fonnd that solvothermally prepared TiO coatings have the ability to kill E. coli. This nniqne property of TiO makes it an ideal candidate in producing self-sterilizing protective masks and in providing bactericidal and self-cleaning properties to a variety of snrfaces. 

Electrooptical properties will be covered only briefly. Fluorocarbons find widespread utility in altering electrooptical properties of coatings. These properties are to be considered as derived from bulk properties of the fluorocarbon. In that regard, fluoropolymers are the most often selected. It is known from Eq. (2) that the electrooptical properties of fluorocarbons can be linked directly to the nature of the C—F bond (a oc n and e <=< n ). It is instructive to consider some relevant values. The dielectric constants e of PTFE, PE, and nylon-6,6 have been determined to be 2.1 (60 Hz-2 GHz), 2.2-2.3 (1 kHz), and 3.6-3.0 (100 Hz-1 GHz), respectively. The dielectric constants for PE and PTFE are comparable. The explanation can be found by comparing segmental polarizabilities a for groups with C—F bonds versus those with C—H bonds, as shown in Table 4.1. They are nearly identical. As e is related to a, it is not surprising that PE and PTFE have similar dielectric constants. The value of e for nylon-6,6 is included above for comparison. 

One of the more interesting initial differences between the tensile properties of coated and uncoated fabric, shown in Table 1, is the decrease in the initial modulus. The Parylene-C coating used in the majority of the tests, 0.75 Jim, was the smallest thickness at which a qualitative change in the handle of this type of fabric was noticed. 

Table 1. Tensile Properties of Coated and Uncoated Modern Silk Fabric...

Thermal Exposures. The thermally Induced changes in tensile properties of coated and uncoated silk fabric, expressed as percent retained breaking-load, strain-to-break and energy-to-break in Figures 2,3, and 4, respectively, are shown with the lines representing the calculated exponential decline. 

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