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Chemical changes in unsaturated oils upon aging and subsequent effects on fabric yellowing and soil removal
Author(s) -
Choe Park Eun Kyung,
Obendorf S. Kay
Publication year - 1994
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/bf02541468
Subject(s) - triolein , squalene , chemistry , soil water , oleic acid , extraction (chemistry) , osmium tetroxide , solvent , accelerated aging , environmental chemistry , chromatography , organic chemistry , biochemistry , environmental science , electron microscope , physics , lipase , soil science , optics , enzyme
Abstract Aging of unsaturated oily soils on polyester/cotton fabric was explored with oleic acid, triolein and squalene as model soils in terms of the relationship between changes in their chemical structure and fabric appearance. Among the three unsaturated oily soils studied, yellowing was observed only with squalene‐soiled and aged fabric swatches after aging for 2 to 46 wk. The yellow material formed upon aging was not completely removed by laundering or organic solvent extraction. In extraction, the more polar solvents removed more yellow material from the fabric. Radiotracer analysis of labeled oily soils showed that all three soils volatilized from fabric upon aging with their characteristic volatility patterns. The amount volatilized increased with aging time and temperature. Removal of triolein and squalene increased remarkably after aging when applied as single soil. Higher aging temperature (40°C) increased soil removal more dramatically than a lower temperature (21°C). In a mixed soil system, removal of triolein by detergency increased up to 8 wk of aging; a decrease in removal was oberved for a specimen aged from 8 to 26 wk at 21°C. Removal of oleic acid decreased gradually during aging in both single and mixed soil systems. Separation of aged products by thin‐layer chromatography (TLC) revealed that unsaturated oily soils chemically changed into various polar oxidation products that were more easily removed by detergency. Infrared (IR) spectra of the aged oils substantiated the appearance of polar groups, such as O−H, C=O and C−O. Osmium tetroxide treatment proved disappearance of double bonds of unsaturated oils upon aging. The fabric yellowing observed for squalene‐soiled fabric is related to the formation of yellow, polar, resinous material due to rapid oxidation, as evidenced by TLC, IR spectra, volatility pattern and rigidity of aged fabric. Oxidation products of squalene with conjugated C=O groups are proposed as the cause of fabric yellowing upon aging, and a possible mechanism for their formation is proposed.