Title

Flash Photolysis of Aromatic Diisocyanate-Based Polyurethanes

Document Type

Article

Publication Date

12-13-1989

Department

Polymers and High Performance Materials

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 indirectly by reaction with a tert-butoxy radical produced upon excitation of tert-butyl peroxide at 351 nm.

Publication Title

ACS Symposium Series

Volume

381

First Page

43

Last Page

56

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