Minig Charlotte, Meißner Alexandra, Steinhaus Martin
Department of Chemistry, TUM School of Natural Sciences, Technical University of Munich, Lichtenbergstraße 4, 85748 Garching, Germany.
Leibniz Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany.
Polymers (Basel). 2024 Dec 21;16(24):3573. doi: 10.3390/polym16243573.
Polyurethane materials, widely used in indoor environments, occasionally exhibit unpleasant odors. An important source of polyurethane odorants is polyether polyols. Previous studies identified odorous 2-ethyldimethyl-1,3,6-trioxocanes in polyurethane materials and polyols but did not investigate the odor activity of the individual isomers. In the present work, an isomer mixture of the precursor dipropylene glycol was fractionated through preparative high-performance liquid chromatography. After the conversion to the corresponding trioxocanes, gas chromatography-olfactometry analyses revealed that just one positional isomer, namely 2-ethyl-4,7-dimethyl-1,3,6-trioxocane, was odor active. Moreover, we observed clear differences in the odor threshold concentrations among its stereoisomers. Only two out of eight isomers displayed an odor, both with an earthy smell and one being approximately 60 times more potent than the other. These insights contribute to a better understanding of polyurethane odor on a molecular level and provide a basis for effective odor control.
聚氨酯材料广泛应用于室内环境，偶尔会散发出难闻的气味。聚氨酯气味物质的一个重要来源是聚醚多元醇。先前的研究在聚氨酯材料和多元醇中鉴定出有气味的2-乙基二甲基-1,3,6-三氧杂环壬烷，但没有研究各个异构体的气味活性。在本研究中，通过制备型高效液相色谱法对前体二丙二醇的异构体混合物进行了分离。在转化为相应的三氧杂环壬烷后，气相色谱-嗅觉测量分析表明，只有一种位置异构体，即2-乙基-4,7-二甲基-1,3,6-三氧杂环壬烷具有气味活性。此外，我们观察到其立体异构体之间的气味阈值浓度存在明显差异。八种异构体中只有两种有气味，都有泥土味，其中一种的气味强度大约是另一种的60倍。这些见解有助于在分子水平上更好地理解聚氨酯气味，并为有效控制气味提供依据。
