Thermal stability and rate order dependence for the thermal decomposition of electro-optic dyes Original Research Article

A variety of electro-optic dyes have been measured by sealed capillary DSC. Thermal decomposition is most often accompanied by an exotherm, sometimes of great thermal intensity. The exotherm is characterized by an onset temperature, as well as a peak temperature. Upon dilution of the dyes in biphenyl or naphthalene solutions, the exotherm onset and peak typically shift to much higher temperatures. Quantitative fits to trial rate expressions suggest that the rate shifts from higher order to a first order decomposition mechanism upon dilution. This kinetic shift suggests strongly that matrices of electro-optic dyes can be best stabilized thermally by isolating the dyes chemically from one to another. Success at such may improve the device thermal stability by as much as 100–150°C.