Resist materials swelling

The vapor vent valves are connected to the tank vapor control valve, and ultimately to the carbon canister by tubing that is resistant to swelling in the presence of fuel vapors. The tubing material must also have a low HC permeation rate, so that the evaporative emissions are not increased due to release of HC molecules. The tank vapor control valve connects the carbon canister to two fuel tank vapor sources the vapor vent valve lines and a refueling vent tube. 

The use of phenolic polymers in photocrosslinkable systems usually involves multicomponent systems which incorporate polyfunctional low molecular weight crosslinkers. For example, Feely et al. [9] have used hydroxymethyl melamine in combination with a photoactive diazonaphthoquinone which produces an indene carboxylic acid upon irradiation to crosslink a novolac resin. Similarly, Iwayanagi et al. [10] have used photoactive bisazides in combination with poly(p-hydroxy-sty-rene) to afford a negative-tone resist material which does not swell upon development in aqueous base. 

The primary considerations for the use of plastic materials in fuel and oil systems include resistance to swelling, softening, or embrittlement. Also important are flexibility and stability under a wide range of temperatures. Information on some common elastomers and plastics used in fuel systems is provided in TABLE 9-8. 

Buna-N This nitrile rubber material has been used extensively in automatic transmissions. It is compatible with most petroleum products, can be formed into a variety of shapes, and is economical. It is useful at temperatures ranging from -40°F to 230°F (-40°C to 110°C). It has excellent resistance to swelling and softening at higher temperatures. 

Fast breeder reactor fuel rods consist of stainless-steel-clad mixed oxide (U,Pu)02 fuel however, more stable alloys for cladding and in-core structural materials, with resistance to swelling and embrittlement under fast neutron irradiation, and more efficient fuels (carbide see 17.3.12.1.2) or nitride (see 17.3.12.3)] are needed h The mechanical, metallurgical, and chemical processes in fuel element irradiation are depicted in Figure 1. Figure 2 shows the PFR (U.K.) fast breeder fuel element, and Figures 3 and 4 illustrate the Fast Flux Test Facility (FFTF) fuel system. 

When a material swells, it produces pressure toward any object resisting the moisture-driven expansion. That is why deck boards on a deck are normally installed with a certain gapping, such as 1/4-3/8-in. between boards (Fig. 12.1-12.3). 

MERCURIC THIOCYANATE (592-85-8) Hg(SCN)i Moderately unstable solid. Possible violent reaction with strong oxidizers strong acids organic peroxides, peroxides and hydroperoxides potassium chlorate potassium iodate, silver nitrate, sodium chlorate, nitric acid. Incompatible with ammonia, chlorates, hydrozoic acid, methyl isocyanoacetate, nitrates, nitrites, perchlorates, sodium peroxyborate, trinitrobenzoic acid, urea nitrate. When heated, this material swells to many times its original bulk. Attacks aluminum in the presence of moisture. Decomposes above 329°F/165°C, releasing toxic mercury and cyanide fumes, and sulfur and nitrogen oxides. On small fires, use dry chemical powder (such as Purple-K-Powder), alcohol-resistant foam, or COj extinguishers. MERCURIC (Spanish) (7439-97-6) see mercury. 

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