Convertible coatings

Gd converter can be used. Both techniques were studied and compared with the common direct neutron imaging with Gd metal converter (0.1mm thick) and single coated fine grained radiographic film, exposed in a vacuum cassette. The unprotected IP ( TR type ) in combination with the Gd metal converter were also exposed in a vacuum cassette. Our experience can summarized as follows ... 

For the parallel recording of EEL spectra in STEM, linear arrays of semiconductor detectors are used. Such detectors convert the incident electrons mto photons, using additional fluorescent coatings or scintillators in the very same way as the TEM detectors described above. 

The extraction of titanium is still relatively costly first the dioxide Ti02 is converted to the tetrachloride TiCl4 by heating with carbon in a stream of chlorine the tetrachloride is a volatile liquid which can be rendered pure by fractional distillation. The next stage is costly the reduction of the tetrachloride to the metal, with magnesium. must be carried out in a molybdenum-coated iron crucible in an atmospheric of argon at about 1100 K ... 

Titanium has potential use in desalination plants for converting sea water into fresh water. The metal has excellent resistance to sea water and is used for propeller shafts, rigging, and other parts of ships exposed to salt water. A titanium anode coated with platinum has been used to provide cathodic protection from corrosion by salt water. 

The hydrogenolyaia of cyclopropane rings (C—C bond cleavage) has been described on p, 105. In syntheses of complex molecules reductive cleavage of alcohols, epoxides, and enol ethers of 5-keto esters are the most important examples, and some selectivity rules will be given. Primary alcohols are converted into tosylates much faster than secondary alcohols. The tosylate group is substituted by hydrogen upon treatment with LiAlH (W. Zorbach, 1961). Epoxides are also easily opened by LiAlH. The hydride ion attacks the less hindered carbon atom of the epoxide (H.B. Henhest, 1956). The reduction of sterically hindered enol ethers of 9-keto esters with lithium in ammonia leads to the a,/S-unsaturated ester and subsequently to the saturated ester in reasonable yields (R.M. Coates, 1970). Tributyltin hydride reduces halides to hydrocarbons stereoselectively in a free-radical chain reaction (L.W. Menapace, 1964) and reacts only slowly with C 0 and C—C double bonds (W.T. Brady, 1970 H.G. Kuivila, 1968). 

Almost all of the OX that is recovered is used to produce phthaUc anhydride. PhthaUc anhydride is a basic building block for plasticizers used in flexible PVC resins, for polyester resins used in glass-reinforced plastics, and for alkyd resins used for surface coatings. OX is also used to manufacture phthalonitrile, which is converted to copper phthalocyanine, a pigment. 

Performance in Colter. The modified monomer should perform well ia commercial deposition equipment. Performance considerations iaclude the growth rate of the coating, the uniformity of thickness of the coating over the chamber volume, and the efficiency with which the dimer is converted to useful coatings on the substrates. 

Acrylics. Acetone is converted via the intermediate acetone cyanohydrin to the monomer methyl methacrylate (MMA) [80-62-6]. The MMA is polymerized to poly(methyl methacrylate) (PMMA) to make the familiar clear acryUc sheet. PMMA is also used in mol ding and extmsion powders. Hydrolysis of acetone cyanohydrin gives methacrylic acid (MAA), a monomer which goes direcdy into acryUc latexes, carboxylated styrene—butadiene polymers, or ethylene—MAA ionomers. As part of the methacrylic stmcture, acetone is found in the following major end use products acryUc sheet mol ding resins, impact modifiers and processing aids, acryUc film, ABS and polyester resin modifiers, surface coatings, acryUc lacquers, emulsion polymers, petroleum chemicals, and various copolymers (see METHACRYLIC ACID AND DERIVATIVES METHACRYLIC POLYMERS). 

Both RDX and HMX are substantially desensitized by mixing with TNT to form cyclotols (RDX) and octols (HMX) or by coating with waxes, synthetic polymers, and elastomeric biaders. Most of the RDX made ia the United States is converted to Composition B (60% RDX, 40% TNT, 1 part wax added). Composition A5 (RDX 98.5/stearic acid 1.5) and composition C4 (RDX91/nonexplosive plasticizer) account for the next largest uses. HMX is used as a propellant and ia maximum-performance plastic bonded explosives such as PBX 9401 and PBX N5 and the octols (147—150). 

A varnish is often appHed on top of the paint layers. A varnish serves two purposes as a protective coating and also for an optical effect that enriches the colors of the painting. A traditional varnish consists of a natural plant resin dissolved or fused in a Hquid for appHcation to the surface (see Resins, natural). There are two types of varnish resins hard ones, the most important of which is copal, and soft ones, notably dammar and mastic. The hard resins are fossil, and to convert these to a fluid state, they are fused in oil at high temperature. The soft resins dissolve in organic solvents, eg, turpentine. The natural resin varnishes discolor over time and also become less soluble, making removal in case of failure more difficult (see Paint and FINNISH removers). Thus the use of more stable synthetic resins, such as certain methacrylates and cycHc ketone resins, has become quite common, especially in conservation practice. 

C2HgNg H4O2P2 (60). The pyrophosphate is reported to be only soluble to the extent of 0.09 g/100 mL water, whereas melamine orthophosphate is soluble to 0.35 g/mL. The pyrophosphate is the most thermally stable. Melamine orthophosphate is converted to the pyrophosphate with loss of water on heating. AH three are available as finely divided soflds. AH are used commercially in flame-retardant coatings (qv) and from patents also appear to have utihty in a wide variety of thermoplastics and thermosets. A detaHed study of the thermal decomposition of the these compounds has been pubHshed (61). 

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