THE PHOTOACTIVE DIAZOSULFONATE GROUP AND ITS ROLE IN POLYMER CHEMISTRY

Diazosulfonates are water soluble, highly photoactive but thermally st able compounds which are prepared from appropriate diazonium salts and sodium sulfite in a diazo coupling reaction. Upon irradiation, the st able trans-isomer is converted into the instable cis-isomer, followed by decomposition via a radical or an ionic mechanism with phenyl radic als or diazonium salts, respectively, as intermediates, depending on t he reaction conditions. These chromophores could be incorporated as si de groups into polymers via copolymerization, copolycondensation or vi a polymer analogous reaction. Reaction conditions as well as advantage s and disadvantages of these different techniques-and the photochemist ry of the polymers are discussed. Diazosulfonate polymers have been ap plied successfully as photoresins in offset printing techniques. The u se in test stripes in quick assays for the detection of phenolic compo unds is discussed based on the coupling reaction of the diazonium salt intermediates. In addition, diazosulfonate containing surfactants cou ld be synthesized and were used as photoactive stabilizers in emulsion polymerization and as partners in photoactive polyelectrolyte-surfact ant complexes.