Polyurethane-based coatings

Use Polyurethane base coating materials for rocket reentry. 

Fig. 7. ASTM B-117 salt spray test results of (a) the chromate conlrol on AA 2024-T3 (b) the acrylate-epoxy based system on AA 2024-T3 (c) the novolac epoxy-polyurethane based coating on AA 2024-T3 (d) the polyurethane-based coating on AA 6061 (e) the epoxy-based system on HDG and (f) the chromate control on HDG [30],...

Conformal coatings are used for PCAs that require exceptional resistance to moisture, solvents, or abrasion. A wide variety of polymers are used to perform this function, including phenolic, silicone and urethane lacquers and sUicone rubber, polystyrene, epoxy, and paraxylylene coatings. Epoxy and polyurethane-based coatings are the most commonly used. H conformal coatings are used in conjunction with a solder mask, they must be chemically compatible. - ... 

First, the nanoparticles were added after the base resin was dissolved in solvent. The obtained mixture was agitated to prepare a uniform mixture. The nanocomposites were prepared by removing the solvent or by polymerization of the monomer. In our research, polyurethane-based coatings reinforced by ZnO nanoparticles (about... 

Polyurethane foams are widely used. Rigid foams, for example, are used in cavity wall insulation in buildings, while flexible foams have, until recently, been used in soft furnishing for domestic use. They continue to be used in car seating. In addition to foams another major use of polyurethanes is in surface coatings. A variety of polyurethane-based polymers, some of considerable complexity, are used for this purpose, but all share the common desirable features of toughness, flexibility, and abrasion resistance. 

In practical application, most types of P.B.15 1 are completely fast to overcoating in oven drying systems. The pigments are suitable candidates for powder coatings, for instance for acrylate or polyurethane-based systems, in which they do not exhibit plate-out (Sec. 1.6.4.1). 

Interest in polyurethane ionomers has increased in the last decade because of their growing uses in water-based coating, adhesives, medical, and semiconductor applications. However, relatively little information has been published regarding the synthesis and... 

Polyesters [2] find use in fibers [poly(ethylene terephthalate), poly(ethylene oxybenzoate), poly(ester ethers), poly(ester amides), etc.] [1], coatings (especially unsaturated polyesters) [4], plasticizers, adhesives, polyurethane base resins, films, etc. Cross-linked polyesters prepared from glycerol and phthalic anhydride (alkyd resins) have been reviewed [20], High-melting poly aryl esters have been investigated for high-temperature applications. 

In general, die position of thermal transitions markedly affects the mechanical behavior of polymeric coatings. IK and 2K polyurethanes based on the IPDI macromer behave as toughened plastics, since the ambient temperature T is... 

Removal of the article from the mold is lengthy process because anti-adhesive lubricants have to be sprayed on the on a mold surface before every injection, in an operation that takes up to 25 - 30% of the full cycle. In reactive molding of polyurethane-based compounds, internal lubricants are used in combination with surface coatings. This allows us to remove articles from a mold many times with a single coating treatment. One of the compounds used as an internal lubricant is silicon-organic liquids. 

A coating described by Worley and coworkers was shown to efficiently kill both on contact and by release [137], The polyurethane-based material contains quarternary ammonium groups for contact-killing and AMialamine groups for releasing chlorine... 

The addition of small amounts of fluorinated polyols to conventional aqueous polyurethane coatings can improve their water resistance and mechanical properties considerably 47 FEVE resins can be applied as water-based coatings and cured at 160°C (320°F) for 25 min to produce coatings with high gloss and good water and weather resistance.48 They may also be cured with water-based hardeners.49... 

REZTHANES 1980A 1980B, aqueous polyurethane base or single coat, is designed for knife over roll or floating knife application on goods normally coated with solvent coatings where either recovery or protected environment is in place. 

For manufacturing composite sandwich panels by laminating, a coating apparatus for the adhesive (chloroprene-base and polyurethane-base adhesives are preferable) and a press is needed. 

Solderable wires are used in telecommunications and the construction of analytical instruments, but they are becoming more and more common in small motors and dry-type transformers. The special characteristic of solderable wire enamels is the direct soldering. When the enameled wire is dipped in a solder bath at temperatures above 350 °C the coating melts and leaves the bare copper wire, avoiding the need for elaborate mechanical or chemical removal of the enamel. This characteristic achieved in solderable poly(ester-imide) by a special polymer composition and in polyurethane based wire enamels is due to the thermally reversible splitting of the polyurethane group. Nevertheless, good thermal stability is necessary and product temperature indexes >155 are required. For temperature indexes of 130, simply polyurethane wire enamels were used. 

Dual Constructions. In addition to the "basic" magnet wire insulations in which the conductor wire is coated with a single enamel, there are a number of cases where two different enamels are used one overcoated over the other. Examples include polyurethane-base insulation overcoated with poly(vinyl butyral) or with nylon, or polyester-base insulation overcoated with nylon or with polyamide imide. 

Since the 1970s a trend to use water-based coating systems and glues instead of solvent-based products has been apparent. Most water-based paints and lacquers use polyurethane or acrylate as binders. For technical reasons the systems still contain organic cosolvents as well as pigments, biocides and surfactants (Hansen et al., 1987). 

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