Nanostructure formation via association of tectons in amorphous polymer matrices

The supramolecular assembling of small amounts of octyl- and benzyl-substituted complementary tectons based upon barbiturates (BA) and 2,4,6-triaminopyrimidines (TP) was studied in a polystyrene matrix by means of differential scanning calorimetry (DSC), dynamic-mechanical spectroscopy, and transmission electron microscopy (TEM). Self-organization of these tectons within the compounds drastically changes the melt rheology in comparison to the pure matrix. Depending on external conditions such as temperature and mechanical deformation, the formation of BA/TP assemblies in polystyrene via self-organization leads to strongly increased dynamic moduli and a networklike behavior. A minimum content of 3 wt% of BA/TP is required for these rheological effects. A similar self-organization and reinforcing effect could not be observed in a more polar poly(methyl methacrylate) matrix. The resulting BA/TP structures were also examined by TEM and polarized light microscopy in both polymer matrices as well as at the interface of sandwiches consisting of PMMA and polystyrene layers. The microscopic techniques confirm the rheological results with respect to the dynamic self-organization and provide information about the concerning morphology development.