Models of the chain packing for the ordered and disordered modifications of the α and β forms of syndiotactic polystyrene are suggested, through quantitative comparisons between X-ray diffraction intensities and calculated structure factors. The kinds of disorder present in both the crystalline forms are also discussed. In the α form the disorder corresponds to the statistical occurrence of two different, nearly isosteric, orientations of triplets of chains at well defined locations of a threedimensional lattice, while in the β form it corresponds to the statistical occurrence of two different kinds of stacking of ordered bilayers of macromolecules. © 1991 Accademia nazionale dei Lincei.
Order-disorder phenomena in the crystalline polymorphic a and β forms of syndiotactic polystyrene / De Rosa, C.; Guerra, G.; Corradini, P.. - In: ATTI DELLA ACCADEMIA NAZIONALE DEI LINCEI. RENDICONTI LINCEI. SCIENZE FISICHE E NATURALI. - ISSN 1120-6349. - 2:3(1991), pp. 227-237. [10.1007/BF03002950]
Order-disorder phenomena in the crystalline polymorphic a and β forms of syndiotactic polystyrene
De Rosa C.;
1991
Abstract
Models of the chain packing for the ordered and disordered modifications of the α and β forms of syndiotactic polystyrene are suggested, through quantitative comparisons between X-ray diffraction intensities and calculated structure factors. The kinds of disorder present in both the crystalline forms are also discussed. In the α form the disorder corresponds to the statistical occurrence of two different, nearly isosteric, orientations of triplets of chains at well defined locations of a threedimensional lattice, while in the β form it corresponds to the statistical occurrence of two different kinds of stacking of ordered bilayers of macromolecules. © 1991 Accademia nazionale dei Lincei.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
