Ion beam analysis of the imidization kinetics of polyamic ethyl ester

The extent of imidization was determined as a function of depth in films of the deuterated version of a model polyimide precursor, polyamic ethyl ester (d-PAE), using a novel ion beam analysis technique. Monitoring the loss of the deuterated ethyl moiety provided a precise means of evaluating the extent of imidization f as a function of the temperature of imidization and time at the imidization temperature. The imidization reaction was found to proceed uniformly as a function of depth down to 700 nm below the surface. The imidization kinetics followed a two-stage sequence in which the initial rate of imidization was rapid, up to f values of ca. 0.6, whereupon the reaction rate diminished sharply. © 1990.