Synthesis of thermotropic polyurethanes containing ester mesogen units and their mesophase behavior

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian-Feng Ban ◽  
Shao-Rong Lu ◽  
Chenxi Zhang ◽  
Ting Liu ◽  
Zhiyi Huang
Keyword(s):  
Melting Point ◽  
Benzoic Acid ◽  
Liquid Crystalline ◽  
Raw Materials ◽  
Triethylene Glycol ◽  
Molar Ratio ◽  
Hydroxybenzoic Acid ◽  
Point Temperature ◽  
Ft Ir ◽  
Lower Temperature

AbstractA series of novel thermotropic liquid crystalline was synthesized from bi(p-hydroxyl benzoic acid)hydroquinone ester (PHQ), triethylene glycol and 2,4- toluenediisocyanate (2,4-TDI) by altering the molar ratio of PHQ and diol, and PHQ was prepared by using hydroquinone and p-hydroxybenzoic acid as raw materials. The thermotropic mesophase behavior, the melting point temperature (Tm) and the isotropization temperature (Ti) of the synthesized polyurethanes were characterized by FT-IR, DSC and POM. It showed that all of the polyurethane polymers exhibited nematic textures at temperature of 110~230 °C. The shift of the melting and isotropization temperature (Tm, Ti) to lower temperature is discussed to be a consequence of the increasing amount of diol content.

Synthesis and Characterization of Biphenylnate Liquid Crystalline Polyurethanes

2010 ◽  
Vol 428-429 ◽  
pp. 158-161 ◽  
Author(s):  
Jian Feng Ban ◽  
Shao Rong Lu ◽  
Chen Xi Zhang
Keyword(s):  
Transition Temperature ◽  
Melting Point ◽  
Diethylene Glycol ◽  
Liquid Crystalline ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Flexible Chain ◽  
Ft Ir ◽  
Thermotropic Properties

A series of novel biphenylnate liquid crystalline polyurethanes (BLCPs) were synthesized by polyaddition reaction of 4,4’-dihydroxybiphenyl with 2,4-TDI(2,4-toluenediisocyanate) and diethylene glycol through changing the molar ratio of diphenol and diol. The thermotropic properties, the melting point (Tm) and the isotropization temperature (Ti) of the synthesized polyurethanes were characterized by FT-IR, DSC, POM and WXRD. The results of experiments showed that all of the polyurethane polymers exhibited thermotropic liquid crystalline properties between 130°C and 230°C. The transition temperature (Tm and Ti) decreased with an increase in the length of the flexible chain.

Synthesis and Characterization of Super-Molecular Ionic Liquids

2011 ◽  
Vol 197-198 ◽  
pp. 906-910
Author(s):  
Hui Ru Liu ◽  
Li Qiang Lv ◽  
Xing Chen Zhang
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Melting Point ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Raw Materials ◽  
Ammonium Thiocyanate ◽  
Molar Ratio ◽  
Molecular Ion

This study concerned a novel super-molecular ionic liquid synthesized by ammonium thiocyanate and caprolactam. The physical characters such as melting point and electric conductivity were investigated. Results showed that the melting point is -12.2°C at the molar ratio of 3:1 (caprolactam/ammonium thiocyanate), which is much lower than raw materials. The electric conductivities of synthesized ionic liquids were close to that of imidazole ILs. The structure of ionic liquid was characterized by IR,1HNMR and quantum chemical calculations. It was shown that the NH4+cation connected with caprolactam organic molecules by hydrogen bonds, leading to the forming of a super-molecular ion. The electrostatic attraction of super-molecular ion with anion was decreased because of the larger volume of super-molecular ion than original cation, thus the melting point decreased. The key properties that distinguish super-molecular ionic liquid from other ILs were the presence of supermolecular ion, which can be used to build up a hydrogen-bonded network. This type ion liquid was named as super-molecular ion liquid.

Semirigid Homo- and Copoly(Imide-Carbonate)s Based on 3,4,3″,4″ -p-Terphenyltetracarboxdiimide

1998 ◽  
Vol 10 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Moriyuki Sato ◽  
Seiji Ujiie ◽  
Yuji Tada ◽  
Takashi Kato
Keyword(s):  
Nematic Phase ◽  
Liquid Crystalline ◽  
Molar Ratio ◽  
Temperature Dependent ◽  
X Ray ◽  
Melt Polycondensation ◽  
Elemental Analyses ◽  
Temperature Ranges ◽  
Ft Ir ◽  
C Nmr

Novel thermotropic liquid crystalline (LC) semirigid homo- and copoly(imidecarbonate)s composed of a 3, 4, 3″, 4″- p-terphenyltetracarboxdiimide ring and aliphatic chains were prepared by melt polycondensation of a dihexanol derivative of 3, 4, 3″, 4″- p-terphenyltetracarboxdiimide and/or a dioxydihexanol of biphenyl taken in a definite molar ratio with hexamethylene diphenyl dicarbonate in the presence of zinc acetate, and their thermal and mesogenic properties were evaluated. The assigned structures of polymers were characterized by FT-IR and 13C NMR spectroscopy, and elemental analyses. DSC and TG-DTA measurements, polarizing microscope observations of textures and temperature-dependent x-ray analyses demonstrated that the polymers have wider LC temperature ranges (nematic phase) than analogous semirigid poly(ester-imide)s and are thermally stable up to 300 °C in air.

Synthesis and Characterization of Zn-Ca-Mg-Al Hydrotacite-Like Compounds and its Application in the PVC

2011 ◽  
Vol 66-68 ◽  
pp. 65-69
Author(s):  
Long Feng Li ◽  
Yuan Gao ◽  
Mao Lin Zhang
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Raw Materials ◽  
Treatment Temperature ◽  
Molar Ratio ◽  
Medium Ph ◽  
X Ray ◽  
Ft Ir ◽  
Thermal Stability Of

Ca-Mg-Al hydrotalcite-like compounds (CaMgAl-HTLcs) were synthesized by a hydrothermal method, and characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) techniques. The effects of the medium pH value, the molar ratio of the raw materials, the reaction temperature and the reaction time on the structure of CaMgAl-HTLcs were studied. The results showed that increasing treatment temperature and reaction time could improve the crystallinity and monodispersity of hydrotalcite-like compound particles. And well-defined CaMgAl-HTLcs could be prepared at a pH value of 10~11 with n(Zn+Mg+Ca):n(Al) =2. The products synthesized were applied to PVC to improve the thermal stability of PVC.

scholarly journals Biodegradable Oligoesters of ε-Caprolactone and 5-Hydroxymethyl-2-Furancarboxylic Acid Synthesized by Immobilized Lipases

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1402 ◽  
Author(s):  
Todea ◽  
Bîtcan ◽  
Aparaschivei ◽  
Păușescu ◽  
Badea ◽  
...  
Keyword(s):  
Melting Point ◽  
Raw Materials ◽  
Polymeric Chain ◽  
Chemical Route ◽  
Renewable Raw Materials ◽  
Immobilized Lipases ◽  
Polymeric Compounds ◽  
Ft Ir ◽  
Candida Antarctica B ◽  
Heterocyclic Structure

Following the latest developments, bio-based polyesters, obtained from renewable raw materials, mainly carbohydrates, can be competitive for the fossil-based equivalents in various industries. In particular, the furan containing monomers are valuable alternatives for the synthesis of various new biomaterials, applicable in food additive, pharmaceutical and medical field. The utilization of lipases as biocatalysts for the synthesis of such polymeric compounds can overcome the disadvantages of high temperatures and metal catalysts, used by the chemical route. In this work, the enzymatic synthesis of new copolymers of ε-caprolactone and 5-hydroxymethyl-2-furancarboxylic acid has been investigated, using commercially available immobilized lipases from Candida antarctica B. The reactions were carried out in solvent-less systems, at temperatures up to 80 °C. The structural analysis by MALDI TOF-MS, NMR, and FT-IR spectroscopy confirmed the formation of cyclic and linear oligoesters, with maximal polymerization degree of 24 and narrow molecular weight distribution (dispersity about 1.1). The operational stability of the biocatalyst was explored during several reuses, while thermal analysis (TG and DSC) indicated a lower thermal stability and higher melting point of the new products, compared to the poly(ε-caprolactone) homopolymer. The presence of the heterocyclic structure in the polymeric chain has promoted both the lipase-catalyzed degradation and the microbial degradation. Although, poly(ε-caprolactone) is a valuable biocompatible polymer with important therapeutic applications, some drawbacks such as low hydrophilicity, low melting point, and relatively slow biodegradability impeded its extensive utilization. In this regard the newly synthesized furan-based oligoesters could represent a “green” improvement route.

scholarly journals Multicomponent Materials to Improve Solubility: Eutectics of Drug Aminoglutethimide

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 40
Author(s):  
Basanta Saikia ◽  
Andreas Seidel-Morgenstern ◽  
Heike Lorenz
Keyword(s):  
Melting Point ◽  
Molar Ratio ◽  
Experimental Characterization ◽  
X Ray ◽  
Eutectic Mixtures ◽  
Ft Ir ◽  
Aqueous Solubilities ◽  
Ft Ir Spectroscopy

Here, we report the synthesis and experimental characterization of three drug-drug eutectic mixtures of drug aminoglutethimide (AMG) with caffeine (CAF), nicotinamide (NIC) and ethenzamide (ZMD). The eutectic mixtures i.e., AMG-CAF (1:0.4, molar ratio), AMG-NIC (1:1.9, molar ratio) and AMG-ZMD (1:1.4, molar ratio) demonstrate significant melting point depressions ranging from 99.2 to 127.2 °C compared to the melting point of the drug AMG (151 °C) and also show moderately higher aqueous solubilities than that of the AMG. The results presented include the determination of the binary melt phase diagrams and accompanying analytical characterization via X-ray powder diffraction, FT-IR spectroscopy and scanning electron microscopy.

Preparation of La–TiO2/Bentonite and Its Photodegradation Properties to Cyanide

2016 ◽  
Vol 16 (4) ◽  
pp. 4233-4238
Author(s):  
Qinglong Wang ◽  
Kexun Chen ◽  
Yali Zhang
Keyword(s):  
Waste Water ◽  
Photocatalytic Activity ◽  
Raw Materials ◽  
Sol Gel ◽  
Molar Ratio ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

The photocatalytic materials were prepared by sol–gel method: the main raw materials were tetrabutyltitanate and the lanthanum nitrate hexahydrate, bentonite was the carrier to support TiO2.The properties of the composites were characterized by specific surface area (BET), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TG). The photocatalytic degradation of cyanide waste water was used to assess the photocatalytic activity of the materials. The experimental results showed that the suitable content of lanthanum and roasted temperature could improve the photocatalytic activity. When the composites were roasted at 400 °C and the molar ratio of La to Ti was 1%, the photocatalyst reached optimal performance.

scholarly journals Synthesis and characterization of some biological active transition metal complexes of Schiff base derived from cefixime with mixed ligand 8-hydroxy quinoline

2015 ◽  
Vol 12 (4) ◽  
pp. 797-807
Author(s):  
Baghdad Science Journal
Keyword(s):  
Melting Point ◽  
Metal Ion ◽  
Bidentate Ligand ◽  
Mixed Ligand ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Hydroxy Quinoline

The aim of the work is synthesis and characterization of bidentate ligand [dipotassium sodium7-((E)-2-(2-((Z)-1-carboxylatoethylideneamino)thiazol-4-yl)-2 (carboxylatemethoxyimino) acet amido)-8-oxo-3-vinyl-5- thia-1-azabicyclo[4.2.0] oct-2- ene-2- carboxylate] [Nak2L], from the reaction of cefixime with sodium pyruvet to produce the ligand [Nak2L], the reaction was carried out in methanol as a solvent under reflux. The prepared ligand [Nak2L] which was characterized by FT-IR, UV-Vis spectroscopy, 1H, 13C-NMR spectra, Mass spectra, (C.H.N) and melting point. The mixed ligand complexes were prepared from ligand [Nak2L] was used as a primary ligand while 8-hydroxy quinoline [Q] was used as a secondary ligand with metal ion M(?).Where M(?) = (Mn ,Co ,Ni ,Cu ,Zn and Cd) at reflux ,using methanol as a solvent, KOH as a base. Complexes of the composition [(M)2(Q)2(KL)(H2O)4] with (2:2:1) molar ratio were prepared. All the complexes were characterized by spectroscopic methods (FT-IR, UV-Vis spectroscopy) along with elemental analysis (A.A), chloride content and melting point measurements were carried out, together with conductivity and magnetic susceptibility. These measurements showed octahedral geometry around (Mn??, Co??, Ni??, Cu??, Zn?? and Cd??) ions. The biological activity of the ligands [NaK2L], [Q] and complexes [(M)2(Q)2(KL)(H2O)4] were studied by using inhibition method.

Condition optimization for synthesis of 5-methyl-2(pyrimidin-2-yl)benzoic acid

2020 ◽  
Vol 17 ◽  
Author(s):  
Fei Liu ◽  
Shengyong Zhao ◽  
Linpo Yu ◽  
Haibiao Liu
Keyword(s):  
Benzoic Acid ◽  
Raw Materials ◽  
Maximum Yield ◽  
Molar Ratio ◽  
High Yield ◽  
Metal Catalyst ◽  
One Pot ◽  
Condition Optimization ◽  
Close Relationship ◽  
Optimum Reaction

: Orexin has been emerged as a hot and frontier research theme in the close relationship with sleep-wake regulation. In this paper, we report a synthetic method for the preparation of 5-methyl-2-(pyrimidin-2-yl)benzoic acid, which is an important molecular fragment of orexin Filorexant (MK-6096). Compared to the previously reported methods, the current route has the advantages of a short synthetic pathway, simple post-treatment, and high yield that provide an effective new methodology for the synthesis of the target compound. Using 2-bromo-5-methyl benzoic acid and 2-chloropyrimidine as raw materials, PdCl2(PPh3)2 is used as a metal catalyst to mediate one-pot generation of 5-methyl-2-(pyrimidin-2-yl)benzoic acid using the Negishi cross-coupling method. The optimum condition involves 2-bromo-5-methylbenzoic acid (10.00 g) and anhydrous zinc chloride powder (6.32 g) together with the catalyst: 2-bromo-5-methylbenzoic acid molar ratio of 0.02 and 2-chloropyrimidine: 2-bromo-5-methylbenzoic acid molar ratio of 1.1:1 at a reaction temperature of 55°C for 14 h. Under these optimum reaction conditions, the maximum yield of 78.4% is attained for 5-methyl-2-(pyrimidin-2-yl) benzoic acid.

Hydrothermal Synthesis and Characterization of Ca-Mg-Al Hydrotacite-Like Compounds

2011 ◽  
Vol 287-290 ◽  
pp. 569-572 ◽  
Author(s):  
Mao Lin Zhang ◽  
Yuan Gao ◽  
Long Feng Li
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Raw Materials ◽  
Treatment Temperature ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Medium Ph ◽  
X Ray ◽  
Ft Ir

Ca-Mg-Al hydrotalcite-like compounds (CaMgAl-HTLcs) were synthesized by a hydrothermal method, and characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) techniques. The effects of the medium pH value, the molar ratio of the raw materials, the reaction temperature and the reaction time on the structure of CaMgAl-HTLcs were studied. The results showed that increasing treatment temperature and reaction time could improve the crystallinity and monodispersity of hydrotalcite-like compound particles. And well-defined CaMgAl-HTLcs could be prepared at a pH value of 10~11 with n (Mg+Ca): n (Al) = 1~3 and n (Mg): n (Ca) = 1~3.

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