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X‐ray diffraction by aluminum soaps
Author(s) -
Marsden Sullivan S.,
Mysels Karol J.,
Smith Gerould H.,
Ross Sydney
Publication year - 1948
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02593315
Subject(s) - stearate , fatty acid , chemistry , aluminium , diffraction , x ray crystallography , x ray , powder diffraction , crystallography , organic chemistry , optics , physics
SummaryThe microphotometer tracings and Bragg spacings of typical x‐ray powder diffraction patterns are reported for aluminum dilaurates and distearates. Patterns for both extracted soaps and soaps containing uncombined acid are included. The extraction of molecular, uncombined fatty acid may produce either a complete recrystallization of the soap, or only minor changes in the diffraction pattern. At least two of the three types of extracted distearate are polymorphs whereas the two types of unextracted stearate are each mixtures of free fatty acid, together with what may be a solid solution of fatty acid in one of the extracted types. Extracted aluminum dilaurate has been observed to exist in only one “crystalline form,” differing from that of the unextracted aluminum dilaurate. The latter consists of free fatty acid, together with dilaurate sorbing some acid with a slight but distinct change in the x‐ray powder pattern. The presence of some free fatty acid in unextracted aluminum soaps is confirmed by x‐rays. The sorption of moisture has no effect on the x‐ray diffraction pattern of aluminum di‐soaps, pointing to purely surface attachment of water.