ISSN:
0570-0833
Keywords:
Long periods
;
Polyethylene
;
Fibers
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Meridional reflections appearing in small-angle X-ray diffraction diagrams of drawn polyethylene are caused by a nearly periodic arrangement of crystalline and disordered regions. The long period, which is determined by the average distance between two consecutive crystallites, depends on the method of preparing the sample. The time and temperature dependences of the positions of the small-angle reflections have been investigated. The growth of the long period of unoriented bulk polyethlene and polyethylene single crystal follows the same time dependence as that of stretched films. However, characteristic differences were obseved in the relationship between density and long period; they are attributed to the fact that in single crystals and in material crystallized from the melt, the chains are folded at the boundaries of the crystallites, whereas this in not the case in stretched polyethylene.
Additional Material:
25 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/anie.196204881
