An Analysis of the Solid Phase Behavior of the Normal Paraffins
260 ## - PUBLICATION, DISTRIBUTION, ETC.
Name of publisher, distributor, etc.
[Gaithersburg, MD] : U.S. Dept. of Commerce, National Institute of Standards and Technology,
Date of publication, distribution, etc.
1962.
500 ## - GENERAL NOTE
General note
/pmc/articles/PMC5310682/
520 ## - SUMMARY, ETC.
Summary, etc.
A set of best values for the temperatures and enthalpies of fusion and transition for the n-paraffins is presented. From an analysis of these data a general qualitative theory of the phase behavior of the n-paraffins is developed. Four distinct crystal structures-hexagonal, triclinic, monoclinic, and orthorhombic-describe the solid phases of all n-paraffins with more than nine carbon atoms in the chain. The latter two structures become equivalent at longer chain lengths. Odd-even differences are resolved in terms of reasonable differences in end group packing, and the smooth increase in melting and transition temperature with increasing chain length is attributed to a decrease in the ratio of end groups to chain groups. Double transitions are predicted for several pure n-paraffins above n-C(34)H(70). Impurity effects are isolated from the pure n-paraffin properties and discussed. The equation, T(M)(°K) = 414.3 (n−1.5)/(n + 5.0) is presented as a correct description of the melting temperatures (T(M)) of all n-paraffins above n-C44H(90). Sufficient data to permit an accurate extrapolation of the enthalpies and entropies of fusion to the infinite-chain limit are not available.
540 ## - TERMS GOVERNING USE AND REPRODUCTION NOTE
Terms governing use and reproduction
540 ## - TERMS GOVERNING USE AND REPRODUCTION NOTE
540 ## - TERMS GOVERNING USE AND REPRODUCTION NOTE
Terms governing use and reproduction
The Journal of Research of the National Bureau of Standards Section A is a publication of the U.S. Government. The papers are in the public domain and are not subject to copyright in the United States. Articles from J Res may contain photographs or illustrations copyrighted by other commercial organizations or individuals that may not be used without obtaining prior approval from the holder of the copyright.
546 ## - LANGUAGE NOTE
Language note
en
690 ## - LOCAL SUBJECT ADDED ENTRY--TOPICAL TERM (OCLC, RLIN)
