Polyoxymethylene combustion

Experiments under subcritical conditions appear to be most promising in this respect. As an example, we may cite a number of works in which different relationships at the extinction limit were used for the determination of the effective activation energy and preexponential factor of the gas-phase combustion reaction. In particular, Krishnamurthy 87) calculated the kinetic parameters of the gas-phase combustion of PMMA from the relationship between the combustion rate and the oxygen pressure and concentration at the extinction limit (Eg = 88 kJ /mol k0 = 3x 1012 cm3/mol s). Other authors 76,94) did the same by analyzing the relationship between the extinguishing oxidant flow velocity and oxidant concentration, with the help of an opposed flow diffusion flame (OFDF) apparatus. A similar relationship between flow velocity and oxidant temperature was suggested, since preheating of the oxidant was found to immediately affect the flame temperature. For PMMA, PE and polyoxymethylene (POM) Eg = 98.5, 140 and 121 kJ/mol, respectively, were reported. 

POLYOXYMETHYLENE GLYCOLS (50-00-0) Forms explosive mixture with air [flash point gas 185°F/85 C flash point solution (methanol content lowers it) 122°-176°F/ 50°-80°C]. Aqueous solutions (37-55% by weight) are combustible and may explode above their flash points. Aqueous solutions slowly oxidize in air to formic acid. May polymerize... 

The heat release rate in the combustion of polyoxymethylene at different oxygen concentrations is shown in Figure 3.39. 

Polymers like polyoxymethylene (POM) and polyethylene terephthalate (PTFE, Teflon), do not form hydrocarbon compounds during combustion and do not exhibit an inclination towards formation of soot. Polyolefins, which form predominantly aliphatic hydrocarbons during pyrolysis, are less inclined to form soot than others like PS, styrene copolymers or ABS, which produce aromatic hydrocarbon [131]. 

Two types of alcohols were investigated bio-methanol and bio-ethanol. Methanol (methyl alcohol) is used as a solvent (soluble in fats, resins and varnishes), also used in the pharmaceutical component of fuel for aircraft (the main component of fuel), explosives (e.g. C4), as fuel in internal combustion engines such as speedway motorbikes, used with caustic solutions or acids to obtain methyl esters, a basic raw material for polyoxymethylene (polyoxymethylene, polyformaldehyde). Ethanol (ethyl alcohol) is widely used in food and pharmaceutical industries (alcoholic fermentation) and cosmetics it is also used as a solvent. Alcohol may also be used to fuel diesel engines if there are good lubrication injector nozzles and the alcohol is mixed with a small (5-20%) amount of oil. 

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