Untersuchungen zu struktur und eigenschaften der polyamide, 2. Einkristalle aus polyamid 6,6

Polyamide 6,6 single crystals have been crystallized from dilute solutions at temperatures between 20 and 150°C and characterized by X-ray wide and small angle scattering, electron microscopy, differential calorimetry and density measurements. It turnes out that morphology, crystal thickness, density, heat of fusion and melting behaviour are strongly influenced by crystallization temperature. The degrees of crystallinity calculated either from density or heat of fusion are found in the range from 40 to 60% depending on crystallization temperature. As a result of annealing at elevated temperatures the long period increases continuously with annealing temperature and time. The obtained results are discussed in detail with regard to a model of polyamide single crystals proposed by KELLER et al. which provides a regular fold structure.