Organic char former

The chemistry of flame-retardant additives is highly varied and is optimised not only for specific polymer chemistries, but also to address flammability effects such as flame spread, dripping, smoke release and so on. Flame-retardant chemistry includes classes of compounds such as halogenated organics, char formers, crosslinking compounds, mineral fillers, intumescent packages, phosphorus compounds, nitrogen-based compounds and even certain metal and boron compounds. 

POLYMER-ORGANIC CHAR FORMERS PVA, STARCH, GLUCOSE DERIVATIVES, POLYFUNCTIONAL ALCOHOLS... 

A polymer-organic char former (PVA system) incorporated in nylon-6,6 reduced the peak rate of heat release from 1124.6 kW/m (for nylon-6,6) and 777.9 kW/m (for PVA) to 476.7 kW/m and increased the char yield from 1.4% (for nylon 6,6) to 8.7% due to a "synergistic" carbonization effect. The cone calorimeter was operated at 50 kW/m incident flux. 

To insure that all the molybdenum in the oil whether present in an organically soluble form or in varying forms as particulate matter would be recorded by AAS, a sulfuric and nitric acid wet digestion process was selected for sample preparation. This process differs from the wet ashing procedure in that the former is carried out in a liquid acid medium from start to finish at a relatively low temperature (280 C), whereas in the wet ashing procedure after acid charring the oil, the char is subjected to a 600 C muffling step. 

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