PHOTOLYSIS, THERMOLYSIS, AND PROTOLYTIC DECOMPOSITION OF A TRIAZENE POLYMER IN SOLUTION

The depolymerization of a triazeno-group containing photopolymer, poly [oxy-1, e-azo(methylimino)hexamethylene(methylimino)azo-1, 4-phenylene ], is investigated in a tetrahydrofuran (THF) solution. Irradiation of the material leads to a dean decomposition of the photolabile polymer , as monitored by UV spectroscopy and gel-permeation chromatography (G PC). As compared to the photolysis in THF solution, the light-induced decomposition rate of a polymer in a polymer film is shown to be much slower. The highly photosensitive triazeno group also decomposes therm ally at temperatures above approx. 220 degrees C. The kinetics of ther mal degradation of the polymer in substance was investigated at a temp erature of 256 degrees C, and monitored by GPC measurements. During th is decomposition, one first observes the development of higher molar-m ass fractions, which result from grafting reactions of primary radical s. Upon further thermolysis the triazene polymer is completely degrade d to low-molar-mass products. The volatile decomposition products were identified by gas chromatography/mass spetrometry (GC/MS) analysis. T he protolytic decomposition, which represents the retrosynthesis of th e triazene polymer, was studied in a 9:1 mixture of tetrahydrofuran an d an aqueous citrate buffer solution. Although the decomposition rate in this solvent mixture is slow, as compared to the depolymerization i n diluted hydrochloric acid, a clean decomposition of the triazene pol ymer is obtained.