Self epoxy coatings

In the hollow flne-flber design, the hollow fibers are a bundle of thousands of parallel, self-supporting, hair-like fibers enclosed in a fiberglass or epoxy-coated steel vessel. Water is introduced into the hollow bores of the fibers under pressure. The permeate water exits through one or more module ports. The concentrate also exits in a separate one or more module ports, depending on the design. All these module designs may be combined into banks of modules and may be connected in parallel or in series. 

Levulinic acid can be converted by known processes to the solvents, tetrahydrofuran and 2-methylfuran, to succinic acid, to 5-aminolevulinic acid for weed control (see Chap. 11) and to diphenolic acid. Diphenolic acid may be useful in waterborne epoxy coatings and other resins. If a suitable acid catalyst that can be left in the resin can be found, it may be possible to convert diphenolic acid, by self-acylation, to an analogue of phenol-formaldehyde resins, thus eliminating the use of the carcinogenic... 

Chem. Descrip. Silicone-modified polyester (51 1%) in solv. mixt. Uses Surf, wetting agent, flow aid, surf. tens, reducer for self-leveling epoxy coatings, sealants... 

Cab-O-SII TS-610 Cab-O-SII TS-720 Ircogel 903 WorldeAdd VP-614 B flow aid, self-leveling epoxy coatings WorldeAdd VP-614 B flow aid, semigloss enamels Rheolate 278 flow aid, semigloss paints Bermodol MAC 2001 flow aid, silicones... 

Figure 11.18 Microcapsule-based self-reporting material amine cured epoxy coating mixed with microcapsules that contained 2, 7 -dichlorofluorescein (DCF), (a) Schematic of the release of DCF solution from broken microcapsules into a crack or scratch where the dye encounters the amine groups of the resin, resulting in colour change, (h) Colour change of a DCF solution in the presence of an amine, (c) Self-reporting properties of the described material.

Panasonic offers both polyester and metallised polyester film capacitors. The non-inductive, high stability, epoxy coated polyester types are also claimed to offer high volumetric efficiency and low losses. Additionally the metallised polyester film types are claimed to be self-healing. Their structure is composed of a number of discrete units to confine and isolate any dielectric breakdown. Panasonic also supplies miniaturised versions whose height and length dimensions are less than 8 mm with a corresponding thickness less than 5 mm. 

Samadzadeh M., Boura S.H., Peikari M., Ashrafi A. and Kasiriha S.M. (2011), Tung oil An autonomous repairing agent for self-healing epoxy coatings. Prog. Org. Coat., 70,383-387. 

Fig. 14. Commercial marine epoxy coating containing (a) adhesion promoter coated >n a steel substrate (b) HOPDMS, PDES, and adhesion promoter (c) TKAS catalyst microcapsules and adhesion promoter (d) the complete self-healing system including HOPDMS, PDES, adhesion promoter, and TKAS catalyst microcapsules. All samples were healed at room temperature (approximately 25"C).

Fig. 20. (a) Optical image of a self-healing sample containing a microvascular network substrate after crac are formed in the epoxy coating, showing the release of the healii agent from the cracks (Scale bar = 5 mm) (b) schematic diagram of a capillary network in the dermis layer of skin with a cut in the epidermis layer. Reprinted from K.S. Toohey, N.R. Sottos, J.A. Lewis, J.S. Moore and S.R. White, Nature Materials, 6, 581—585 (2(X)7) with permission from Macmillan Publishers Ltd. 

Polymeric overlays are used on concrete pavements to protect them from dust, excessive wear, cracking, crazing, spalling and to provide an attractive appearance. These materials are applied on concrete pavements in the form of screeds, self-levelling material or floor coatings. Epoxies, polyurethanes and acrylics are commonly used, epoxies being the most commonly chosen. Table 1.4 gives the suitability of these materials for different environments. 

Epoxies have an excellent resistance to abrasion. The abrasion resistance of a particular system depends upon the type of formulation and conditions. For example coatings have the capacity to resist abrasion from rubber wheels, whereas screed floorings, repair mortar and self-levelling floors can resist thousands of cycles from steel wheels. 

The thermoset acrylics (20) of major importance in the coating industry, in recent years, have been developed primarily by Canadian Industry Ltd. and by Pittsburgh Plate Glass Co. in this country (4). Raw materials are acrylamide, acrylic acid, acrylates, and styrene. Cross-linking agents are amino and epoxy resins. The materials are also self-cross-linking. They are usually sold as solutions in paint solvents. 

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