74294-94-3Relevant academic research and scientific papers
Cholesterol ester compound and preparation method and application thereof
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Paragraph 0027, (2018/09/11)
The invention discloses a cholesterol ester compound and a preparation method and application thereof and relates to the field of manufacture of lubricant modifiers. The cholesterol ester compound hasthe following molecular structure, wherein n is one of 6, 8, 10, 12, 14 and 16, and m is one of 2, 4, 6, 8 and 10. An intermediate product is generated from cholesterol and a binary acid under activator and catalyst condition; the intermediate product is subjected with secondary esterification with any one of 1-hexanol, 1-octanol, 1-decanol, 1-dodecanol, 1-tetradecanol, and 1-hexadecanol; the cholesterol portion in the cholesterol lipid compound is of angled sheet structure; such structure, polarity of ester groups and hydrotropy of long-chain alkyl synergically allow the cholesterol esters to be possibly applicable to lubricant additives; the cholesterol ester compound may act as a lubricant friction modifier applied in lubricant production.
New amphiphilic polycarbonates with side functionalized cholesteryl groups as biomesogenic units: synthesis, structure and liquid crystal behavior
Xu, Xiaoxu,Liu, Xiaofeng,Li, Qun,Hu, Jianshe,Chen, Qifan,Yang, Liqun,Lu, Yanhua
, p. 14176 - 14185 (2017/03/11)
The synthesis of four new amphipathic copolymers with side functionalized-cholesterol based aliphatic polycarbonates is described through the ring-opening polymerization and coupling reaction. The chemical structures, liquid crystal (LC) behavior, and thermal stability of the chiral monomers and copolymers obtained in this study were characterized using Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, gel permeation chromatography (GPC), polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) measurements. The effect of the spacer length on the molecular interaction and mesophase of the chiral monomers and copolymers was investigated. It was found that chiral monomers with longer spacer seemed beneficial for the formation of mesophases, and the additional ordering on polymerization caused mesophases to be more ordered than for the corresponding monomers. The LC copolymers all revealed a smectic A phase with an interdigitated molecular arrangement. The results seemed to show a decreased tendency toward the glass transition temperature, and isotropic temperature for the LC copolymers by increasing the spacer length. In addition, four LC copolymers had a good thermal stability.
A new class of star-shaped cholesteric liquid crystal containing a 1,3,5-trihydroxybenzene unit as a core
Yao, Dan-Shu,Zhang, Bao-Yan,Zhang, Wei-Wei,Tian, Mei
, p. 83 - 89 (2008/12/20)
A new class of star-shaped cholesteric liquid crystals were designed and synthesized, which used 1,3,5-trihydroxybenzene unit as a core and ω-cholesteric alkyl diacid monoester as mesogenic arm. Their chemical structures were confirmed by element analyses, FT-IR, and 1H NMR. The mesomorphic properties and thermal stability were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. The experimental results demonstrated that the mesogenic arm structures strongly affected the phase behavior. 4a did not show any liquid crystallinity, while 4b, 4c and 4d revealed reversible cholesteric phase transition. As the intermedius alkyl chain of the star-shaped compounds lengthened (from n = 2 to n = 8), their melting points decreased but mesomorphic temperature ranges increased. Focal conic texture, one of cholesteric phase can be observed in the liquid crystalline state.
