Structure and properties of polyethyleneterephthalate crystallized by annealing in the highly oriented state

摘要: The structure of polyethyleneterephthalate bristles drawn about five times in the amorphous state and subsequently crystallized at temperatures between 100 260‡ C has been studied by means small-angle X-ray scattering. In addition density, heat fusion wide-angle scattering behaviour were measured. For comparison, similar experiments carried out with undrawn samples. results showed that degree crystallinity PET cannot be calculated from density data on basis a simple two-phase model, since effective densitiesρc* andρa* crystalline regions depend strongly crystallization drawing conditions. With rising temperature size mosaic blocks building up layers their longitudinal mutual order increase whereas volume fraction region is only rather slightly effected annealing temperature. difference densityρc* “X-ray density”ρc supposed to caused lattice vacancies boundaries blocks.