The crystal structure of the emptied clathrate form (delta(e) form) of syndiotactic polystyrene, obtained by removing the guest molecules from different clathrate delta forms, is presented. Chains in s(2/1)2 helical conformation are packed in the monoclinic unit cell with axes a = 17.4 Angstrom, b = 11.85 Angstrom, c = 7.70 Angstrom, and gamma = 117 degrees according to the space group PS1/a. The crystalline density of the emptied clathrate form (0.977 g/cm(3)) is lower than that of the amorphous phase (1.055 g/cm(3)). The differences between the structures of the emptied clathrate form and clathrate delta forms are discussed by the analysis of X-ray diffraction patterns and packing energy calculations.
Crystal structure of the emptied clathrate form (delta(e) form) of syndiotactic polystyrene / DE ROSA, Claudio; G., Guerra; V., Petraccone; Pirozzi, Beniamino. - In: MACROMOLECULES. - ISSN 0024-9297. - STAMPA. - 30:(1997), pp. 4147-4152. [10.1021/ma970061q]
Crystal structure of the emptied clathrate form (delta(e) form) of syndiotactic polystyrene
DE ROSA, CLAUDIO;PIROZZI, BENIAMINO
1997
Abstract
The crystal structure of the emptied clathrate form (delta(e) form) of syndiotactic polystyrene, obtained by removing the guest molecules from different clathrate delta forms, is presented. Chains in s(2/1)2 helical conformation are packed in the monoclinic unit cell with axes a = 17.4 Angstrom, b = 11.85 Angstrom, c = 7.70 Angstrom, and gamma = 117 degrees according to the space group PS1/a. The crystalline density of the emptied clathrate form (0.977 g/cm(3)) is lower than that of the amorphous phase (1.055 g/cm(3)). The differences between the structures of the emptied clathrate form and clathrate delta forms are discussed by the analysis of X-ray diffraction patterns and packing energy calculations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
