Other Coating Systems

Le McAllister, Multidirectionally reinforced carbon/graphite matrix composites, Reinhart TJ ed.. Engineered Materials Handbook, Vol 1, Metals Park, OH, ASM International, 915, 1987. 

Buckley JD, Carbon-carbon an overview, Ceram Bull, 67, 364, 1988. 

Pastore C, Modelling of three dimensional braided carbon-carbon composites, Dayton, Ohio, 1989. 

Huettner W, Potential of Carbon-carbon composites in structural materials, Figueiredo, Bernardo CA, Baker RTK, Hiittinger KJ eds.. Carbon Eibers Filaments and Composites, Kluwer, Dordrecht, 275-300, 1990. 

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Fig. 1 compares the performance of PVDF resin-based coating systems with competitive coatings for their weather resistance. Panels coated with Kynar 500 and other coating systems were exposed on a South Florida test fence for 10-17 yr. The top of the panels was unexposed while the lower part was exposed to sunlight for 10-17 yr. It was concluded that Kynar 500 PVDF offers superior color retention, greater gloss retention, and better resistance to chalking than other systems tested. 

In addition to the five groups of urethane coatings described here, other coating systems have been developed that are described as follows. 

Several higher homologs of phenol such as p-tertiary butyl phenol, p-tertiary amyl phenol and p-tertiary octyl-phenol are used to make oil-soluble phenolic resins for varnishes and other coatings systems. What structural features of these compounds make oil solubility of the resins possible ... 

Changing the powder can present a problem with this system becuase the procedure is long and difficult compared to procedures used with other coating systems. Another disadvantage is spray formation, which prevents powder deposition in small openings and tight angles. Also, because of the resistivity of the powder, thick films, in excess of 0.008 in. (0.03 mm), can be difficult to deposit. 

P(2) Paint or other coating systems used on FRP surfaces shall be compatible with the FRP resins and shall be approved by the resin manufacturer. 

Other Coatings Systems Developed to Reduce VOC Emissions... 

It is recommended practice in the petrochemical industry to provide environmental corrosion protection with hot-dip galvanizing for aU anchors in exterior applications. Other coating systems may be used, but they are not as common and may be more expensive. 

As an alternative to hot-dip zinc coating, mechanical galvanizing (electro-deposited zinc, an inorganic zinc-rich paint, or other coating system specifically selected for corrosion protection), can be used. Mechanical galvanizing should conform to ASTM B695. 

From the preceding discussions it should be clear that waterborne systems will not replace all other coating systems in the foreseeable future. There will be a place for every technology, with some dominating. Solvent based systems will continue to be used, particularly if incinerators or solvent recovery are already in place. Solvent free and water free systems also have an important role to play in the future use and applications of acrylic resins for surface coatings. 

Solvent emission restrictions, as for other coating systems, have also given rise to the development of water-borne, HS, radiation cured and powder PU coating systems. The various techniques which are used to obtain anionic, nonionic and cationic emulsions have been reviewed in the literature. Curing of cationic latex takes place either by reaction of water " with the terminal isocyanate groups or by reaction with water-soluble diamines according to reactions (49) and (50). 

System 1 alone stayed in the same region nearly to the value of 10 ohm cm even after 30 days of immersion in NaCl, indicating no damage to the coating. However, the impedance value of the resistance of the other coating Systems 2, 3 and 4 descended to 10 and 10 ohm cm as the days progressed (Figures 3.12 and 3.13). 

Other coating systems contain cationically modified copolymers obtained by polymerization of acrylic monomers in presence of unsaturated polyurethane macromonomer [22], and water-dilutable dispersions of cationically modified and urethane modified methacrylic copolymers obtained by solution polymerization [23]. 

Solv. for cellulose esters and other coating system. Frequently used in adhesives. Used as extractant in extraction-separation and extraction-photometric detns., e.g. extraction of Fe(//7), Mo, W, Nb, Au(///) (from halide and SCN media). Misc. organic solvs. Sol. H2O (2%). df 0.801. Bp 116.8°. 1.3969. 

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