Polymer coating systems

On the other hand, metal/polymer coating systems are of interest because polymers have the potential to protect metals from the expensive onslaught of corrosion (over 20 billion dollars annually are spent in the U.S. for materials to replace corroded items)4). Polymer coatings can protect metals by acting as barriers, thus preventing the formation of a complete corrosion cell and the spread of corrosion from an initial corrosion site 5). 

LI Temperatme-resistant polymer coating systems for frying, cooking and baking utensils X (MC,CMQ... 

Cao, H, Zhang, R, Sundar, CS, Yuan, J-P, He, Y, Sandreczki, TC, Jean, YC. 1998. Degradation of Polymer Coating Systems Studied by Positron Annihilation Spectroscopy 1. UV Irradiation Effect. Macromolecules, 31, 6627. 

Zhang, J., Polycarpou, A.A., Economy, J. (2010) An improved tribological polymer-coating system for metal surfaces. Tribol. Lett., 38, 355-365. 

The sparing solubility of these multifunctional inhibitor compounds lend themselves more readily to incorporation into paints as slow-release corrosion protection. To avoid possible interference of rare earths elements with epoxy polymer coating systems, as has been observed, an encapsulation mechanism may be considered to successfully incorporate rare earth organic inhibitors into paint formulations. This would limit any detrimental interaction, while still allowing the release of an inhibitor as required. 

Extmsion technology is used to produce spunbond, meltblown, and porous-film nonwovens. Fabrics produced by these systems are referred to individually as spunbonded, meltblown, and textured- or apertured-film nonwovens, or genericaHy as polymer-laid nonwovens. These fabrics are produced with machinery associated with such polymer extmsion methods as melt-spinning, film casting, and extmsion coating. In polymer-laid systems, fiber stmctures are simultaneously formed and manipulated. 

Fig. 3. Polymerization initiation and propagation by radiation-generated free radicals. A is the initiating radical produced by irradiating the Hquid coating. (1) represents the Hquid monomer—unsaturated polymer reactive coating system. R is functional. (2) is the growing polymer chain (free radical). The cured...

Polymers. The molecular weights of polymers used in high energy electron radiation-curable coating systems are ca 1,000—25,000 and the polymers usually contain acryUc, methacrylic, or fumaric vinyl unsaturation along or attached to the polymer backbone (4,48). Aromatic or aUphatic diisocyanates react with glycols or alcohol-terrninated polyether or polyester to form either isocyanate or hydroxyl functional polyurethane intermediates. The isocyanate functional polyurethane intermediates react with hydroxyl functional polyurethane and with acryUc or methacrylic acids to form reactive p olyurethanes. 

Examples of typical photoinitiator systems used to cure reactive coating systems are as follows (80,81). The reactive systems are primarily unsaturated acryUc acid esters of different alcohol and polymer stmctures. 

The acetates of most alcohols are also commercially available and have diverse uses. Because of their high solvent power, ethyl, isopropyl, butyl, isobutyl, amyl, and isoamyl acetates are used in ceUulose nitrate and other lacquer-type coatings (see Cellulose, esters). Butyl and hexyl acetates are exceUent solvents for polyurethane coating systems (see Coatings Urethane polymers). Ethyl, isobutyl, amyl, and isoamyl acetates are frequentiy used as components in flavoring (see Flavors and spices), and isopropyl, benzyl, octyl, geranyl, linalyl, and methyl acetates are important additives in perfumes (qv). 

Typically RO systems are preceded by pretreatment units to remove suspended solids/colloidal matter and add chemicals that control biological growth and reduce scaling. Membranes are typically made of synthetic polymers coated on a backing (skin). Examples of membrane materials include polyamides, cellulose acetate and sulfonated polysulfone. 

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