INFLUENCE OF PROCESSING ON MECHANICAL-PROPERTIES AND MORPHOLOGY OF PET

The deformation behaviour of polybutylene terephthalate depends to a decisive extent on the processing conditions. The latter determine the crystallization conditions and thus also the morphology. The spherulite and lamellar structure of injection moulded PBT, crystallized in the laboratory, is examinded by means of light microscopy, small-angle light scattering and transmission electron microscopy. Differences in the lamellar thickness distribution can be detected by thermoanalysis through changes in the melting behaviour. The mechanical behaviour of injection moulded PBT is investigated in standard test bars by the tensile and tensile creep tests and interpreted on the basis of the morphological data.