Synthesis, Characterization and Adsorption Performance of Semi-crystalline/Liquid Crystalline Polyether Chelating Resins

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Shuangqing Zhang ◽  
Chaocan Zhang ◽  
Changhai He ◽  
Jun Xu
Keyword(s):  
Adsorption Capacity ◽  
Chemical Structure ◽  
Liquid Crystalline ◽  
Selective Adsorption ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Adsorption Ability ◽  
H Nmr ◽  
Chelating Resins ◽  
Crystal Polymer

AbstractA series of polyether chelating resins with pendent biphenyl mesogenic groups were synthesized, and the chemical structure of monomers and polymers were confirmed by IR and 1H NMR detection. The thermal properties of resins were investigated by the Differential Scanning Calorimetry (DSC) and Polarizing Microscopy (POM), and the results showed that only the product of polyepichlorohydrin grafted with 4-cyano-4’-hydrobiphenyl, i.e., HPCN resin, was a kind of nematic liquid crystal polymer with typical schlieren texture (70-130 0C) and other resins were semi-crystalline. The results of adsorption experiments showed that all five resins exhibited a higher adsorption capacity (>1.0 mmol/g) for Cu (II) and Hg (II) and medium adsorption ability for Cd (II), Zn (II), Pb (II) and Co (II), however, a poor adsorption capacity (<0.3 mmol/g) for Mg (II), indicating that this type of polyether resins have a better selective adsorption for above metal ions. In addition, the adsorption capacity of HPnCP resins was generally higher than that of HPd and HPCN owing to the existence of terminal pyrrole coordination groups in HPnCP resins.

scholarly journals Preparation of Series Schiff Bases and Studying of their Liquid Crystalline Behavior

2019 ◽  
Vol 1 (1) ◽  
pp. 17-23
Author(s):  
Bari Muhamd Islamallah
Keyword(s):  
Liquid Crystal ◽  
Chemical Structure ◽  
Liquid Crystalline ◽  
Terminal Group ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Scanning Calorimetry ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Terminal Chain

Our study deals with   preparation   of two types of imine compounds differ in the type of terminal group, where one of them has a terminal carboxyl group COOH while the other contains methoxyOCH3 as a terminal group. In the first part of this research it was Identification by spectroscopy methods using infrared IR and nuclear magnetic resonance H NMR spectrum, besides elemental analysis shows the exact chemical structure of the expected synthesized compounds. In the second part was the study of liquid-crystalline behavior by polarized optical microscopy POM and differential scanning calorimetry DSC that showed a liquid crystal phase in the compounds that has odd number of carbon atoms in the terminal chain compounds in the first series, while the second series compounds showed liquid crystal phase in the   compounds that containing even number of atoms of carbon in the terminal chain. DOI: https://doi.org/10.5281/zenodo.3376373

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

Thermotropic behavior of sodium cholesteryl carbonate

2009 ◽  
Vol 24 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Rabkwan Chuealee ◽  
Timothy S. Wiedmann ◽  
Teerapol Srichana
Keyword(s):  
Phase Behavior ◽  
Chemical Structure ◽  
Liquid Crystalline ◽  
Polarized Light ◽  
Wave Number ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
C Nmr

Sodium cholesteryl carbonate ester (SCC) was synthesized, and its phase behavior was studied. The chemical structure was assessed by solid-state infrared spectroscopy based on vibration analysis. The wave number at 1705 and 1276 cm−1 corresponds to a carbonyl carbonate and O–C–O stretching of SCC, respectively. Molecular structure of SCC was further investigated with 1H and 13C NMR spectroscopy. The chemical shift, for the carbonyl carbonate resonance appeared at 155.5 ppm. A molecular mass of SCC was at m/z of 452. Differential scanning calorimetry (DSC), video-enhanced microscopy (VEM) together with polarized light microscopy, and small-angle x-ray scattering (SAXS) were used to characterize the phase behavior as a function of temperature of SCC. Liquid crystalline phase was formed with SCC. Based on the thermal properties and x-ray diffraction, it appears that SCC forms a structure analogous to the type II monolayer structure observed with cholesterol esters.

SYNTHESIS AND CHARACTERIZATION OF NEW THERMOTROPIC LIQUID CRYSTALLINE POLYURETHANES WITH BIPHENYL MOIETY

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4487-4492 ◽  
Author(s):  
JONG BACK LEE ◽  
SANG PILL LEE ◽  
JIN KYUNG LEE
Keyword(s):  
Liquid Crystalline ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Infrared Study ◽  
H Nmr ◽  
X Ray Scattering ◽  
Phase Transition Temperatures ◽  
No Weight Loss ◽  
Ft Ir ◽  
Tolylene Diisocyanate

A new series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, and 1,4-phenylene diisocyanate, with 4,4□-bis(9-hydroxynonoxy)biphenyl (BP9). Structures of the monomer and the corresponding polymers were identified using FT-IR and 1 H NMR spectroscopic methods. BP9 exhibited a smectic type mesophase, however, nematic phase was found for all synthesized liquid crystalline polyurethanes except for 1,4-phenylene diisocyanate/BP9 based polyurethane. Their phase transition temperatures and thermal stability were investigated by differential scanning calorimetry (DSC), optical polarizing microscopy, and X-ray scattering. The infrared study indicated that the hydrogen bonding among urethane linkages attributed to the mesomorphism. Thermal gravimetric analysis (TGA) of synthesized polyurethanes showed that no weight loss of the polymers observed up to 280°C.

Liquid crystalline hyperbranched polyesters with phosphorus functional groups

2020 ◽  
pp. 095400832096053
Author(s):  
Diana Serbezeanu ◽  
Ana-Maria Macsim ◽  
Ionela-Daniela Carja ◽  
Corneliu Hamciuc ◽  
Marius Pislaru ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Initial Decomposition Temperature ◽  
Molar Ratios ◽  
H Nmr ◽  
Hyperbranched Polyesters ◽  
Hyperbranched Poly ◽  
C Nmr

Liquid crystalline hyperbranched poly(aryl ester)s (A2B3) were prepared by polycondensation reaction of 2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)1,4-naphthalene diol with 1,3,5-benzenetricarbonyl trichloride, taken in two different molar ratios. The chemical structure of the newly synthesized hyperbranched polymers was confirmed by FTIR, 1H NMR, 13C NMR spectroscopy. The polymers exhibited high thermal stability with initial decomposition temperature above 410–435°C and char yield at 700°C higher than 40%. Combined differential scanning calorimetry, polarized optical microscopy and wide-angle X-ray diffraction measurements were carried out to closely examine their thermal behavior and phase transitions.

scholarly journals Dielectric properties of a bisimidazolium salt with dodecyl sulfate anion doped with carbon nanotubes

2018 ◽  
Vol 9 ◽  
pp. 164-174 ◽  
Author(s):  
Doina Manaila Maximean ◽  
Viorel Cîrcu ◽  
Constantin Paul Ganea
Keyword(s):  
Carbon Nanotubes ◽  
Electric Conductivity ◽  
Liquid Crystalline ◽  
Electrode Polarization ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Low Frequencies ◽  
H Nmr ◽  
Dodecyl Sulfate ◽  
High Dielectric

A new bisimidazolium salt with dodecyl sulfate as counterion has been designed and prepared. This salt shows a SmA phase that is stable at room temperature. The new ionic liquid crystal (ILC) was characterized by 1H NMR, 13C NMR and IR spectroscopy. Its liquid crystalline properties were analyzed by polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD) studies. The dielectric spectra of the ILC doped with different concentrations of carbon nanotubes (CNT) were recorded over a wide frequency and temperature range of 10−1 to 107 Hz and 293–338 K, respectively. The values of the activation energy were found in the range of 0.46–0.61 eV; the characteristic time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami functions. As a result of doping the ILC with CNT, the electric conductivity increases significantly. Ionic conductivity is dominant and it was indirectly observed through the electrode polarization (EP) effect. The very high dielectric permittivity values and the decrease of the electric conductivity at low frequencies confirm the presence of EP.

Odd-Carbon Alkyl-Substituent Effect on Liquid Crystalline Properties of Discotic Hexa-Peri-Hexabenzocoronene Molecule

2011 ◽  
Vol 239-242 ◽  
pp. 3358-3361 ◽  
Author(s):  
Xu Ying Liu ◽  
Yu Jiang ◽  
Wen Guang Wang ◽  
Jia Ling Pu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Self Assembly ◽  
Grignard Reagent ◽  
Liquid Crystalline ◽  
Alkyl Substituent ◽  
Electronic Interaction ◽  
Scanning Calorimetry ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Benzene Rings

Hexa-peri-Hexabenzocoronene (HBC), as the smaller graphene fragment consisting of 13 fused benzene rings, possesses a strong tendency to stack together via π-electronic interaction. In this paper, the 1,2-(4-bromomethyl-1-yl) acetylene was alkylated by Grignard reagent to form corresponding 1,2-bis(p-pentadecanylphenyl)acetylene. Cobalt(0)-catalyzed cyclotrimerization was carried out to give hexaphenylbenzene analogue. This step was followed by intramolecular cyclodehydrogenation to yield the desired product HBC-C15. The identity and purity of the new compound was confirmed by UV-vis spectrometer and 1H NMR spectrum. Its thermal behavior and self-assembly were studied by differential scanning calorimetry and polarizing optical microscopy.

scholarly journals Rheological Investigation of Self-emulsification Process

2009 ◽  
Vol 12 (1) ◽  
pp. 17 ◽  
Author(s):  
Shailesh V Biradar ◽  
Ravindra S Dhumal ◽  
Anant Paradkar
Keyword(s):  
Liquid Crystalline ◽  
Bound Water ◽  
Tween 80 ◽  
Cubic Phase ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Rheological Analysis ◽  
Mesophase Formation ◽  
High Level ◽  
Emulsification Process

PURPOSE Aim of this study is to investigate the mechanism of self-emulsification through rheological analysis of intermediate liquid crystalline (LC) phase formed during self-emulsification process. METHODS Binary system of tween 80 (T80) and imwitor 742 (I742) was used and different SES were prepared with I742 at 10, 30, 50, 70 and 90% w/w concentration levels. Self-emulsification was monitored by visual observations and droplet size measurement. Mesophases obtained by 50% v/v hydration of SES were utilized for polarizing microscopy, differential scanning calorimetry and rheological studies. RESULTS Good emulsification with nano sized droplets was observed for SES 30% as compared to micron sized droplets for other SES. In polarizing microscopy, formation of intermediate LC phase was observed in all SES. Lamellar phase was evident in 30% SES while other SES exhibited micellar cubic phase. Presence of high level of structurally bound water in thermal analysis confirmed mesophase formation in all SES. In frequency sweep, decrease in elastic modulus, and an increase in phase degree and loss tangent was observed for 30% SES. Exactly opposite trend was seen in other SES. Thus, rheological studies concluded presence of weak and fragile mesophase structure in 30% SES while LC phase structure with little structural buildup was observed in other SES. This weak mesosphere structure in SES 30% presented no or very little resistance against strain induced deformation. Therefore, during emulsification, weak mesophase in SES 30% ruptured with ease and released jet of nanosize droplets compared to coarse droplets for other SES. CONCLUSION This study signifies the effect of viscoelastic properties of intermediate LC phase on self-emulsification performance.

scholarly journals Liquid Crystalline Compounds in the Thiophene Series, Part 6+ Synthesis and Characterization of Azomethines and Vinylenes with Two Mesogenic Groups and Different Alkylene Spacer Lengths

1993 ◽  
Vol 48 (6) ◽  
pp. 826-843 ◽  
Author(s):  
Gerhard Koßmehl ◽  
Frank Dirk Hoppe ◽  
Barbara Hirsch
Keyword(s):  
Aromatic Amines ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Alkyl Chains ◽  
Liquid Crystalline Phases ◽  
Smectic Mesophase ◽  
Methylene Groups

Compounds which have two mesogenic groups with and without terminal alkyl chains containing thiophene systems, were prepared from α.ω-bis(5-formyl-2-thienyl)alkanes (3a-3n) and various aromatic amines or 2-fluorenyl-Wittig-salt (10). The liquid crystalline properties of these compounds were characterized by differential scanning calorimetry (DSC) and polarizing microscopy. Only the series of α.ω-bis{5-[N-(4′-butyloxybiphenyl-4-yl)imino]formyl-2-thienyl}alkanes (7a-71) showed enantiotropic smectic and nematic mesophases. The series of E,E-α.ω-bis[5-(2-fluorenylvinyl)-2-thienyl]alkanes (8a-81) showed enantiotropic nematic mesophases for the compounds with 4 and 6 methylene groups, monotropic nematic mesophases for the compounds with 7—12 methylene groups and no liquid crystalline phases for compounds with 3, 5, 16 methylene groups in the connecting alkylene chain. In contrast to the compounds 8a-81, E-l-(5-butyl-2-thienyl)-2-(2-fluorenyl)ethylene has a smectic mesophase.

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