Hydrogen cyanide, from decomposition polymers

We have examined a number of materials in terms of toxic gas evolution during pyrolysis or combustion. For example, the products from fibreglass insulations included isocyanic acid and hydrogen cyanide, while the support backing and adhesive of a made-up panel produced acetic acid, acetaldehyde and vinyl chloride as well. The effect of a fire in a confined space such as a surface ship or submarine can be imagined. The products come from thermal decomposition of polymer coatings etc, and while the experimental conditions may not duplicate those of a fire, the information is very useful. 

By-products formed during their preparation (e.g., ethylbenzene and divin-ylbenzenes in styrene acetaldehyde in vinyl acetate) added stabilizers (inhibitors) autoxidation and decomposition products of the monomers (e.g., peroxides in dienes, benzaldehyde in styrene, hydrogen cyanide in acrylonitrile) impurities that derive from the method of storage of the monomer (e.g., traces of metal or alkali from the vessels, tap grease etc.) dimers, trimers, and polymers that are generally soluble in the monomer, but sometimes precipitate, for example, polyac-rylOTiitrile from acrylonitrile. Likewise, in polycondensation reactions it is important to remove reactive impurities because they can cause considerable interference during the polyreaction. 

Hazardous decomposition products Toxic gases and vapors (such as hydrogen cyanide, oxides of nitrogen, and carbon monoxide) may be released in a fire involving acrylonitrile and certain polymers made from acrylonitrile. 

---