Elame

Element Wavelength, nm Elame emission Elame atomic absorption Electrothermal atomic absorption Argon ICP Plasma atomic fluorescence... 

Properties Heat- resistant Extrusion Heat- resistant High-impact Elame- retarded Platable 20% glass-reinforced... 

Stolzberg, R. J. Screening and Sequential Experimentation Simulations and Elame Atomic Absorption Spectrometry Experiments, /. Chem. Educ. 1997, 74, 216-220. 

Pentaerythritol is used in self-extinguishing, non dripping, flame-retardant compositions with a variety of polymers, including olefins, vinyl acetate and alcohols, methyl methacrylate, and urethanes. Phosphoms compounds are added to the formulation of these materials. When exposed to fire, a thick foam is produced, forming a fire-resistant barrier (see Elame retardants) (84—86). 

J. Carnahan and co-workers, "Investigations into the Mechanism for Phosphoms Elame Retardancy in Engineering Plastics," Proc. 4th Inti Conf. Fire Safety, Product Safety Corp., San Erancisco, Calif., 1979. 

Acetylene is condensed with carbonyl compounds to give a wide variety of products, some of which are the substrates for the preparation of families of derivatives. The most commercially significant reaction is the condensation of acetylene with formaldehyde. The reaction does not proceed well with base catalysis which works well with other carbonyl compounds and it was discovered by Reppe (33) that acetylene under pressure (304 kPa (3 atm), or above) reacts smoothly with formaldehyde at 100°C in the presence of a copper acetyUde complex catalyst. The reaction can be controlled to give either propargyl alcohol or butynediol (see Acetylene-DERIVED chemicals). 2-Butyne-l,4-diol, its hydroxyethyl ethers, and propargyl alcohol are used as corrosion inhibitors. 2,3-Dibromo-2-butene-l,4-diol is used as a flame retardant in polyurethane and other polymer systems (see Bromine compounds Elame retardants). 

The newer open-ceU foams, based on polyimides (qv), polyben2imida2oles, polypyrones, polyureas, polyphenylquinoxalines, and phenoHc resins (qv), produce less smoke, are more fire resistant and can be used at higher temperatures. These materials are more expensive and used only for special appHcations including aircraft and marine vessels. Rigid poly(vinyl chloride) (PVC) foams are available in small quantities mainly for use in composite panels and piping appHcations (see Elame retardants Heat-RESISTANTPOLYA rs). 

Elame-spread and smoke-density values, and the less often reported fuel-contributed semiquantitive results of the ASTM E84 test and the limited oxygen index (LOI) laboratory test, are more often used to compare fire performance of ceUular plastics. AH building codes requite that ceUular plastics be protected by inner or outer sheathings or be housed in systems aH with a specified minimum total fire resistance. Absolute incombustibHity cannot be attained in practice and often is not requited. The system approach to protecting the more combustible materials affords adequate safety in the buildings by aHowing the occupant sufficient time to evacuate before combustion of the protected ceUular plastic. 

M. S. Cresser, Elame Spectrometry in Environmental Chemical Analysis A Practical Guide, Royal Society of Chemistry, Cambridge, U.K., 1994. 

Flame Retardants. Bromine compounds make up an important segment of the market for flame retardants used in polymers. Additive flame retardants are added to polymers during processing reactive flame retardants react chemically to become part of the polymer chain itself. In addition to the compounds Hsted in Table 3, a number of proprietary mixtures and phosphoms—bromine-containing flame retardants are also sold (see Elame RETARDANTS, HALOGENATED, FLAAffi RETARDANTS). 

Vinyl chloride polymers are produced in two main types, homopolymers and copolymers, usually with vinyl acetate. Both types can be plasticized by a wide variety of plasticizers (qv), usually esters. Rigid or unplasticized PVC is used extensively for pipe. The plasticized material is used largely in floor coverings. The homopolymer itself is inherently fire-resistant, but addition of plasticizers, unless they are especially fire-resistant, considerably reduces this characteristic (see Elame retardants). 

Elame Arrester A flame arrester is a device permeable to gas flow but impermeable to any flame. It quenches the flame and cools the products sufficiently to prevent reignition at arrester outlet. Arresters are used to prevent a flame propagating into the system from outside (such as via a tank vent) or one part of the system to another (such as through connected piping). 

EIW Mewes, K Albermann, M Blihr, D Erishman, A Gleissner, J Elam, K Eleumann, K Kleme, A Maierl, SG Oliver, E Pfeiffer, A Zollner. Overview of the yeast genome. Nature 387(6634 Suppl) 7-65, 1997. 

EE Elams, MR Sullivan, PD Popken-ElaiTis. J Biomol Stiaict Dyn 15 407-430, 1997. 

To simulate the effect of small flames that may result from faulty conditions within electronic equipment, the lEC 695-2-2 Needle Elame Test may be used. In this case a small test flame is applied to the sample for a specified period and observations made concerning ability to ignite, extent of burning along the sample, flame spread onto adjacent material and time of burning. 

Elam, C.F. (1935) Distortion of Metal Crystals (Clarendon Press, Oxford). 

Alkaline earth metals and transition metals Elame atomic absorption spectrometry ... 

Chromium and inorganic compounds of chromium in air Elame atomic absorption spectrometry 12/2... 

Particulate lead and lead Elame atomic absorption... 

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