Structural features of molecular composites based on polyimide and nylon-6

The samples of a triple Nylon-6-polyimide-Nylon-6 block copolymer containin g 5 and 15% of polyimide (PI) were studied by DSC and X-ray diffraction in the WAXS and SAXS modes. Crystalline regions in the block copolymers studie d comprise small Nylon-6-polyamide (PA) grains (predominantly in the a modi fication), which are subjected to rather insignificant influence of the rig id imide blocks squeezed out into the amorphous phase. The samples with 15% PI contain a small fraction of the crystalline Nylon-6 gamma* phase, which is related to hindered crystallization of the PA chains in the presence of PI. Analysis of the results of SAXS measurements shows that the structure of samples is most adequately described by a two-phase model with a crystal line phase of Nylon-6 and an amorphous phase comprising a mixture of PA and PI chains; Increased mechanical and thermal properties of the copolymers, as well as their high moisture resistance, can be explained using a concept of molecular composites comprising a flexible PA matrix reinforced by rigi d PI fragments.