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Flame treatment Surface pretreatment method, especially for plastics, by means of an acetylene, propane or butane flame burning in excess oxygen. Results in improved surface wettability by the adhesive due to the chemical entrapment of oxygen atoms in the polymer surface. 

A compound of formula C14H12 gave a positive Baeyer test and burned with a yellow, sooty flame. Treatment with ozone followed by hydrolysis in the presence of zinc gave formaldehyde as one of the products. Also isolated from the ozonolysis reaction was a second compound, C13H10O, which birmed with a yellow, sooty flame, and readily formed a semicarbazone with a melting point of 164 °C. The NMR spectrum of this compound (C13H10O) showed only complex multiplets that were near 7.5 ppm the fuUy H-decoupled NMR spectrum showed only 5 peaks. 

Flame treatment is widely used to prepare polyolefin surfaces for adhesive bonding, particularly in labelling operations. This method is purported to burn-off contaminants and weak boundary layers, and also produces surface oxidation. Although flame treatment can be readily automated on a container labelling line, it is very impractical for most product assembly operations. 

The surface burning characteristics (flame spread index and smoke developed index) for wood and wood products as measured by American Society for Testing and Materials (44) can be reduced with fire retardant treatments, either chemical impregnation or coatings (48). Fire retardant treatments also reduce the heat release rate of a burning piece of wood (49,50). The heat release rates (51) of the burning materials are an important factor in fire growth. 

Flame Cleaning Now little used as a preparatory method, flame cleaning is a process whereby an intensely hot oxyacetylene flame is played on the surface of the steel. In theory, differential expansion causes millscale to detach. In practice, there is evidence that the treatment may not remove thin, tightly adhering millscale. Also, steel less them 5 mm thick can buckle. Finally, the process can burn in chemicals deposited on the surface, causing premature paint failure. 

Chemical Reactions. It burns with a luminous flame and is readily expld (Ref 2). It is reduced with Zn dust and Na hydroxide to dimethyl hydrazine (Ref 2). Action of coned HC1 forms methylhydrazine and formaldehyde (Ref 2). Treatment in anhyd eth with Na metal forms a solid adduct which gives dimethylhydrazine on addn of w (Ref 4). For a review of thermal and photochem reactions see Ref 8 Explosive Limits. In mixts with air the crit press at which exp] occurs varies inversely with temp betw 350 and 380° (Ref 6)... 

As in the soap bubble method, only fast flames can be used because the adiabatic compression of the unbumed gases must be measured in order to calculate the flame speed. Also, the gas into which the flame is moving is always changing consequently, both the burning velocity and flame speed vary throughout the explosion. These features make the treatment complicated and, to a considerable extent, uncertain. 

Concentrated sulphuric acid Heat a little of the solid salt with concentrated sulphuric acid carbon monoxide is evolved which may be ignited and burns with a blue flame. All cyanides, complex and simple, are decomposed by this treatment. 

Numerous end uses for cotton depend on its ability to be treated with chemical agents that confer flame resistance. The chemical FR treatments used to confer flame resistance to untreated cotton depend on many factors [358] is the finish intended to be durable or nondurable is the treatment used is to prevent burning or smoldering what is the... 

Another flame-retardant treatment for wool based on exhanstion of an anionic species is the use of tetrabromophthalic anhydride, TBPA (Fig. 8.16), which hydrolyses to the carboxylic form during application. Use of TBPA at 10 % on weight of fabric under acid conditions provides effective flame retardancy that is dnrable to dry cleaning and mild laundering conditions (cold water washing at nentral pH). But TBPA is suspected to generate polybrominated dioxins under burning conditions. 

Polyester fabrics when burned exhibit a melt-drip behaviour. Since the fabric melts away from the flame, some polyester fabric constructions can actually pass vertical flame tests without any flame-retardant treatment. The waiving of melt-drip specifications for children s sleepwear has allowed untreated polyester garments to be sold into that market. 

The data of Madorsky and coworkers have been confirmed by the experiments of Holmes and Shaw, who pyrolyzed several samples of cotton fabrics, before and after treatment with a variety of flame retardants, and found a correlation between the amount of tar and the flammability of the fabric. These authors reported that the tar was highly flammable and burned vigorously when made into a coating on a strip of glass tape that simulated cotton fabrics. 

Portland cement is an aluminosilicate powder which sets to a solid mass on treatment with water. It is usually manufactured by grinding limestone and clay to a fine powder, mixing with water to form a slurry, and burning the mixture, with a flame of gas, oil, or coal dust, in a long rotary kiln. At the hot end of the kiln, where the temperature is about 1500 C, the aluminosilicate mixture is sintered together into small round marbles, called clinker. The clinker is ground to a fine powder in a ball mill (a rotating cylindrical mill filled with steel balls), to produce the final product. Over 100,000,000 barrels of cement per year is made in the United States. 

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