Ostwaldt Jan-Erik, Hirschhäuser Christoph, Maier Stefan K, Schmuck Carsten, Niemeyer Jochen
Faculty of Chemistry (Organic Chemistry) and Centre for Nanointegration Duisburg- Essen (CENIDE), University of Duisburg-Essen, Universitätsstraße 7, 45141 Essen, Germany.
Evonik Operations GmbH, Kirschenallee, 64293 Darmstadt, Germany.
Beilstein J Org Chem. 2021 Jan 12;17:105-114. doi: 10.3762/bjoc.17.11. eCollection 2021.
We report novel supramolecular polymers, which possess a reversed viscosity/temperature profile. To this end, we developed a series of ditopic monomers featuring two self-complementary binding sites, either the guanidiniocarbonyl pyrrole carboxylic acid (GCP) or the aminopyridine carbonyl pyrrole carboxylic acid (ACP). At low temperatures, small cyclic structures are formed. However, at elevated temperatures, a ring-chain transformation leads to the formation of a supramolecular polymer. We demonstrate that this effect is dependent on the concentration of the solution and on the polarity of the solvent. This effect can counteract the loss of viscosity of the solvent at elevated temperatures, thus opening an application of our systems as viscosity index improvers (VIIs) in working fluids. This was tested for different motor oils and led to the identification of one compound as a promising VII.
我们报道了具有反向粘度/温度曲线的新型超分子聚合物。为此，我们开发了一系列具有两个自互补结合位点的双位单体，即胍基羰基吡咯羧酸（GCP）或氨基吡啶羰基吡咯羧酸（ACP）。在低温下，会形成小的环状结构。然而，在高温下，环链转变会导致超分子聚合物的形成。我们证明这种效应取决于溶液的浓度和溶剂的极性。这种效应可以抵消高温下溶剂粘度的损失，从而使我们的体系作为工作流体中的粘度指数改进剂（VIIs）得到应用。这已针对不同的机油进行了测试，并确定了一种化合物作为有前景的VII。
