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8684953 
Journal Article 
Freezing Points of a Number of Pure Hydrocarbons of the Gasoline Boiling Range and of Some of their Binary Mixtures 
Smittenberg, J; Hoog, H; Henkes, RA 
1938 
Yes 
Journal of the American Chemical Society
ISSN: 0002-7863
EISSN: 1520-5126 
60 
1 
17-22 
English 
Freezing point determinations were made of a number of carefully purified hydrocarbons with boiling points within the gasoline boiling range. All the normal paraffins examined crystallized readily and showed no or only slight undercooling. Several iso-paraffins, chiefly those with a strongly branched but symmetrical structure, also crystallized easily. Many other iso-paraffins, on the other hand, showed considerable undercooling. Some iso-paraffins, particularly those which possess an asymmetrical carbon atom, could not be brought to crystallization at all and solidified to a glass. In the case of some other iso-paraffins, which crystallized readily but with a small heat of crystallization, transition points were observed on further cooling. After a varying degree of undercooling, all the naphthenes and aromatics examined could be brought to crystallization; transition points were observed with cyclopentane and cyclohexane. In addition to published data, we also studied a number of freezing point diagrams of binary hydrocarbon mixtures. As a rule there is a eutectic point and the freezing point curves of the components conform to the formula for the ideal freezing point curve. There is probably an interrupted series of mixed crystals in the n-octane-n-nonane system and a continuous series of mixed crystals in the 2,2,3-trimethylbutane-2,2,3,3-tetramethylbutane system. Most of the binary iso-paraffin mixtures produced glass formation. 1938, American Chemical Society. All rights reserved.