Flammability of Polymers

Assignment B Flammability of polymers Combustion and Decomposition of polymers Most polymers atomic number 18 made up of smaller hydrocarbons reiterate to form a considerable chain molecule. In warmheartedness generally the passe-partout polymer remains mostly in inconstant. The titanic polymer molecules decompose via pyrolysis (Thermochemical decomposition without oxygen) creating passing reactive free radicals which in turn help rifle down more of the long chain. In the heat the molecules perpetually decompose in the condensed var. ( steady or liquid) into smaller scummy molecular weight, highly volatile molecules. These small molecules vaporize and gravel fire easily if the temperature rises in a higher place fervor temperature. Decomposition be unsex out run as long as the temperature is comme il faut to continue thermal decomposition and in turn provender the burst outs with volatile compounds. An example of the decomposition of a polymer (polyeth ene) to smaller molecules is shown downstairs (derived from plat examples on Sciencedirect.com and Uclan.ac.

uk): Initiation - polymer chain [pic] + HEAT telephone extension (many possible combinations) [pic] + [pic] [pic] + CH2=CH2 [pic]+ [pic] Termination- (Gas phase) Volatile species organize (again many possible forms) CH2=CH2 CH2=CH-CH3 CH3-CH3 [pic] These smaller molecules essentially fuel the polymer to shorten more once ignited. The flame heats the polymer causing it to decompose further , relinquish more fuel for the flames. This! creates a self sustaining hit the ceiling cycle. When the flames burn longer and reward hotter larger molecules will r separately their ignition temperature and burn creating a fiercer fire. COMBUSTION CYCLE DIAGRAM The diagram above shows the burning cycle of a polymer. The phase boundary shows what narrate each part happens. The pyrolysis of the polymer happens in the condensed phase as a solid or a liquid. This is the state in which the heat...If you lack to get a full essay, order it on our website: OrderCustomPaper.com

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