Part I: J. appl. Chem., Lond., 1969, 19, 39
Fischer-tropsch waxes. II. Crystallinity and physical properties†
Article first published online: 4 MAY 2007
Copyright © 1969 John Wiley & Sons, Ltd
Journal of Applied Chemistry
Volume 19, Issue 3, pages 86–88, March 1969
How to Cite
le Roux, J. H. (1969), Fischer-tropsch waxes. II. Crystallinity and physical properties. J. Appl. Chem., 19: 86–88. doi: 10.1002/jctb.5010190307
- Issue published online: 4 MAY 2007
- Article first published online: 4 MAY 2007
- Manuscript Received: 7 OCT 1968
The density, congealing point, and hardness were considered in relation to crystallinity, determined by an infra-red spectrometric method, of a series of waxes which are fractions from crude Fischer–Tropsch wax. Values ranging between 65 and 93, expressed as molecular percentages of crystalline material present, have been obtained. Data on molecular weights and physical properties were available. Smooth curves could be drawn for the variations of density, congealing point and hardness (or rather penetration) with molecular weight, but only for the more highly crystalline waxes. Two waxes, with crystallinities below 75, were found to have abnormally low congealing points and densities and to be abnormally soft, in relation to their molecular weights. This can be explained in terms of the less dense packing of molecules in the amorphous state.
The effect of crystallinity on density was examined more closely, and a set of equations expressing the relationship between these entities and molecular weight was derived. These contain an unknown factor, however, which is dependent upon molecular weight distribution.