Thermal decomposition kinetics of some aromatic azomonoehters - Part II. Non-isothermal study of three liquid crystals in dynamic air atmosphere

Thermal analysis of three azomonoether dyes, exhibiting liquid-crystalline properties, was performed in dynamic air atmosphere. Thermal stability studies and the evaluation of the kinetic parameters of each physical or chemical transformations are essential for a full characterization, before attempting accurate thin films' depositions of such materials used in non-linear optical applications. New synthesized dyes with general formula: [GRAPHICS] where R is a nematogenic group: CN, CF3 or a highly polarizable group: NO, were investigated using TG, DTG, DTA and DSC techniques, under non-isothermal regime. The evolved gases were analyzed by FTIR spectroscopy. The activation energies of the first decomposition step were evaluated for each compound, the obtained results revealing complex mechanisms.