Cluster structure of poly(amic acid) and polyimide film surfaces

The surface structure of poly(amic acid) and polyimide films of different c hemical composition and morphology was studied by the electron microscopy t echnique with gold decoration. Based on the cluster lattice model, the corr elation radius xi, the lattice density, and the fractal dimensionality of a ggregates (clusters) of macromolecules on the film surfaces were calculated from the spatial distribution parameters of the decorating gold particles. It was shown that radial distribution functions g(R) for the cluster densi ty on the scale R less than or equal to xi follow the power law g(R) simila r to R-eta for a correlation function of the order parameter in the two-dim ensional space, where eta is the critical index equal to 0.20 +/- 0.03. The evolution trends of the cluster structure of poly(amic acid) films in the solid-state thermal imidization process were revealed.