Specific use of electron microscopic techniques in the characterization of ABS polymers

The supermolecular structure of various types of ABS polymers was characterized by employing various preparation and electron-microscopic observation techniques. The results thus obtained were compared with the classical techniques of preparation of ultra-thin sections. The techniques were chosen so as to reveal the structure of the interior of the sample and the rubber particles (material contrast on cut surfaces, separation of particles by dissolving the matrix, fracture at low and high temperatures), the surface structure (surface etching) and the mechanism of the fracture process (fracture surface at room temperature). By treatment of the fracture surfaces (relaxation in vapours of the solvent of the matrix or OsO 4-staining), rubber particles on the fracture surface or adjacent to it can be revealed. The size distribution of rubber particles, determined by using one sample and most of the methods mentioned above, shows an agreement in the range of the most frequently occurring particles. Systematic deviations in the range of large particles (aggregates) are explained by differences between the individual preparation methods.