Neutron scattering studies on the crystallization of polymers

Abstract

The morphology of semicrystalline polymers can be described to a good approximation as consisting of lamellar crystallites separated by amorphous regions. The way in which a single macromolecule traverses the crystalline and amorphous phases can be evaluated from neutron scattering studies of mixtures of deuterated and protonated samples of the same polymers. A new method is proposed for the evaluation of the neutron scattering data without introducing detailed structural models. The only assumption made is that the molecular structure can be described as consisting of “clusters” of crystalline stems which belong to the same molecule. It is shown that this cluster model can be verified experimentally for the cases of poly(ethylene oxide), polypropylene and polyethylene. The spatial correlation of the crystalline stems within a cluster can be evaluated from the scattering data by introducing a direct correlation function c(x). The method was checked by Monte-Carlo calculations and applied to the neutron scattering data of poly(ethylene oxide) (PEO) in the wide angle range. The fraction of stems occupying adjacent sites in the crystal lattice depends strongly on crystallization conditions. © 1985 The Society of Polymer Science, Japan. All Rights Reserved.