title: An epistemology on the nature of polymers.
abstract: Liquids have neither a periodic structure nor the completely random character of gases therefore the detailed study of their x-ray scattering diagram encounters many difficulties. The idea of periodic regularity in molecules of liquid polymers has been an attractive proposition for the simple interpretation of liquid polymer x-ray diagrams. The categorisation of polymer substances as being between a crystal phase with a perfect order and an amorphous disordered state is an over simplification of the complex reality. For obtaining structural information, during the early stages of the application of x-ray diffraction, a near crystalline model of the molecular arrangements in liquids was utilised. However, the results from these investigations led to just an approximation of the crystalline state. Our studies have analysed the real image of Fourier space of liquid polymers, for the first time, using anomalous diffractometry. The findings show the precise atomic structure of liquid polymers when transformed, by cooling, to solid polymers. We demonstrate that there is an intermediate ordered structure, characterised by the real full image of Fourier space. This prominent state of matter, an intermediate ordered structure, is defined by a regular unit cell with a five-fold symmetry. These structural atomic studies contribute to a more detailed understanding of the properties of polymers than the traditional studies of the degree of crystallinity.
authors.affiliation: Laboratoire de Physique des Solides, Université de Paris-Sud, Orsay, France.
authors.forename: Mortéza
authors.initials: M
authors.lastname: Laridjani
authors.affiliation: CNRS - UMR7225, Paris, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Leboucher
mesh_terms: D002138:Calibration; D004058:Diffusion; D005583:Fourier Analysis; D008958:Models, Molecular; D008968:Molecular Conformation; D044367:Phase Transition; D011092:Polyethylene Glycols / Q000737:chemistry*; D013057:Spectrum Analysis; D013696:Temperature
chemical_list: D011092:Polyethylene Glycols