Analysis of the surface morphology, structure and properties of polyamidoimide nanocomposites with tubular hydrosilicates

The surface morphology, structure and transport properties of polyamidoimide (PAI) films prepared from poly(diphenyloxidiamido-N-phenylphtalimidene) synthesized by low temperature polycondensation, and composites with chrysotile-type hydrosilicate nanotubes (NTs) based on it are investigated using АFМ (atomic force microscopy), X-ray diffraction analysis and pervaporation methods. The dependence of the free surface morphology of PAI films on their thicknesses is found: the minimal value of the roughness parameters is achieved at a film thickness of 15 μm, in this case the minimal value of the sizes of macromolecular “nodules” is also recorded, which is 50 nm. It is established that upon the introduction of NTs up to 7 wt % into PAI films with a thickness of 35 μm, the mesomorphic polymer structure is retained. An antibatic dependence of the nanocomposite transport characteristics on surface roughness parameters is detected. The maximal value of the ideal separation factor for a methanol-cyclohexane mixture is demonstrated to correspond to a composite containing 1 wt % of NTs and possessing minimal values of the surface-roughness parameters.