ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Small-angle x-ray scattering has been used to characterize a variety of polyethylene fibers of the so-called shish-kebab type. These fibers are aggregates of elementary fibrils each consisting of a backbone with a lamellar overgrowth. Intense scattering is due to voids between the lamellae giving rise to a “Bragg maximum” reflecting the ordering of lamellae along the backbones. It can be described by rather broad distributions for both the interlamellar spacings and the lamellar thicknesses. This is shown by comparing experimental scattering curves with SAXS patterns calculated on the basis of the theory for one-dimensional scattering of linearly ordered lamellar systems, using the general paracrystalline model. A negative exponential distribution for the center-to-center distance of the lamellae, characteristic of a random nucleation process, apparently cannot be employed for the description of these shish-kebab morphologies. From a discussion on the discrepancies between experimental and theoretical scattering curves it is concluded that the fibers may be inhomogeneous with respect to the statistics of lamellar ordering. This may be due to the nonisothermal character of the crystallization process.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1980.180180502
