ISSN:
0887-6266
Keywords:
polyethylene, linear and branched, X-ray diffraction and 13 C-NMR characterization of
;
x-ray diffraction of linear and branched polyethylenes
;
nuclear magnetic resonance (NMR) study of linear and branched polyethlenes
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
X-ray diffraction patterns of linear and branched polyethylenes typically show two sharp reflections and an amorphous halo. The position of the halo depends on branch content and temperature. A single curve describes the position of the halo maximum (2θhalo) for a range of liquid hydrocarbons and polyethylenes in the 20-140°C range. At temperatures well below their melting point, branched polymers give 2θhalo values which differ significantly from those observed for the liquid Linear polymers show a greater divergence, indicating that some of the material giving rise to the halo is much better packed than in the liquid.Parallel 13 C NMR spin-lattice relaxation studies suggest that this relatively ordered material has a trans conformation but a low average T1c value. © 1993 John Wiley & Sons, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/polb.1993.090310206
Permalink
