Accession Number : ADA192278

Title :   Flash Photolysis of Aromatic Diisocyanate Based Polyurethanes.

Descriptive Note : Technical rept.,

Corporate Author : UNIVERSITY OF SOUTHERN MISSISSIPPI HATTIESBURG DEPT OF POLYMER SCIENCE

Personal Author(s) : Hoyle, C E ; No, Y G

PDF Url : ADA192278

Report Date : 10 Mar 1988

Pagination or Media Count : 33

Abstract : The laser flash photolysis of aromatic diisocyanate based polyurethanes in solution provides evidence for a dual mechanism for photodegradation. One of the processes, an N-C bond cleavage, is common to both TDI (toluene diisocyanate) and MDI (methylene 4,4' -diphenyldiisocyanate) based polyurethanes. The second process, exclusive to MDI based polyurethanes, involves formation of a substituted diphenylmethyl radical. The diphenylmethyl radical, which readily reacts with oxygen, is generated either by direct excitation (248 nm) or by reaction with a tert-butoxy radical produced upon excitation of tert-butyl peroxide at 351 nm.

Descriptors :   *PHOTOLYSIS, *POLYURETHANE RESINS, AROMATIC COMPOUNDS, EXCITATION, FLASHES, ISOCYANATES, LASERS, OXYGEN, TOLUENES, PHOTODEGRADATION, CHEMICAL BONDS, PEROXIDES, LASER APPLICATIONS

Subject Categories : Radiation and Nuclear Chemistry
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE