NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Thermal Decomposition Chemistry of Poly(vinyl alcohol).


pdf icon Thermal Decomposition Chemistry of Poly(vinyl alcohol). (1343 K)
Gilman, J. W.; VanderHart, D. L.; Kashiwagi, T.

Chapter 11; ACS Symposium Series 599;

American Chemical Society. Fire and Polymers II: Materials and Tests for Hazard Prevention. National Meeting, 208th. ACS Symposium Series 599. August 21-26, 1994, Washington, DC, American Chemical Society, Washington, DC, Nelson, G. L., Editor(s), 161-185 pp, 1995.

Keywords:

fire retardants; flame retardants; thermal decomposition; char formation; additives; flammability; pyrolysis; morphology; residues; gasification; thermogravimetric analysis; polyvinyl acetate; calorimetry

Abstract:

The fundamental condensed phase processes which lead to char formation during the fire-like pyrolysis of poly(vinyl alcohol), PVA, and PVA-containing maleimides were characterized using CPM/AS 13C NMR. In addition to evidence of the well known chain-stripping elimination of H2O and the chain-scission reactions, which occur during the pyrolysis of pure PVA, evidence is presented in support of cyclization and radical reaction pathways responsible for the conversion of unsaturated carbons into aliphatic carbons. Two general mechanisms; one described as a physical encapsulation, and the other a lowering of the average volatility of certain degradation products, are proposed for the primary modes of action of maleimides on the pyrolysis of PVA.