Synthesis and Characterization of Stilbene Derivatives for Possible Incorporation as Smart Additives in Polymers Used as Packaging Films.

1997 ◽  
Vol 50 (4) ◽  
pp. 425 ◽  
Author(s):  
Gary M. Day ◽  
Owen T. Howell ◽  
Michael R. Metzler ◽  
Paul D. Woodgate
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Packaging Films ◽  
Multiple Phase ◽  
Liquid Crystalline Phases ◽  
Crystal Properties ◽  
Stilbene Derivatives

Several series of stilbene derivatives for possible use as smart additives in polymers used as packaging films have been prepared and characterized. Differential scanning calorimetry was performed on some of the stilbenes in order to determine any liquid crystal properties. Those compounds which had multiple phase transitions were also shown to have two liquid crystalline phases according to optical microscopy.

scholarly journals Synthesis, Mesomorphism and the Optical Properties of Alkyl-deuterated Nematogenic 4-[(2,6-difluorophenyl)ethynyl]biphenyls

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4653
Author(s):  
Jakub Herman ◽  
Piotr Harmata ◽  
Michał Czerwiński ◽  
Olga Strzeżysz ◽  
Marta Pytlarczyk ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Optical Properties ◽  
Liquid Crystalline ◽  
Near Infrared ◽  
Synthesis And Characterization ◽  
Molecular Approach ◽  
Scanning Calorimetry

The synthesis and characterization of new deuterated liquid crystal (LC) compounds based on phenyl tolane core is described in this paper. The work presents an alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic and optical properties for compounds which are alkyl-hydrogen terminated and alkyl-deuterium, have been drawn. The compounds are characterized by mass spectrometry (electron ionization) analysis and infrared spectroscopy. They show enantiotropic nematic behavior in a broad temperature range, confirmed by a polarizing thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesized compounds show a significantly reduced absorption in the near-infrared (NIR) and medium-wavelength infrared (MWIR) radiation range, and stand as promising components of medium to highly birefringent liquid crystalline mixtures.

Synthesis and Characterization of Segmented Copolymers of a Methylated Polyamide and a Thermotropic Liquid Crystalline Polyester

1989 ◽  
Vol 171 ◽  
Author(s):  
Gregory T. Pawlikowski ◽  
R. A. Weiss ◽  
S. J. Huang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Composite Material ◽  
Block Copolymer ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Segmented Copolymers ◽  
Liquid Crystalline Polyester ◽  
Solution Polycondensation

ABSTRACTA block copolymer consisting of liquid crystalline polyester segments and methylated polyamide segments has been synthesized. Solution polycondensation of acid chloride end-capped poly(terephthaloyl phenylhydroquinone) (LCP portion) with an amine terminated poly(N,N'-dimethylethylene sebacamide) was utilized to prepare the block copolymer. Characterization by differential scanning calorimetry, infrared spectroscopy, thermogravimetric analysis, optical microscopy and elemental analysis has been performed to verify the existence of the block copolymer that may have potential as a molecular composite material or self-reinforcing thermoplastic.

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.

Synthesis and Characterization of Hyperbranched Liquid Crystalline Polymer

2010 ◽  
Vol 428-429 ◽  
pp. 98-101
Author(s):  
Chen Xi Zhang ◽  
Shao Rong Lu ◽  
Jian Feng Ban
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Liquid Polymer ◽  
Thermotropic Properties

Hyperbranched liquid crystalline polymer (HLCP) were prepared by pentaerythritol with 1,2,4-benzenetricarboxylic anhydride(BTCA) and p-hydroxy benzoic acid. The thermotropic properties, the melting point (Tm) and the isotropization temperature (Ti) of the synthesized HLCP were characterized by differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR) and polarizing optical microscopy (POM). It showed that the new reactive thermotropic liquid polymer containing polyester mesogenic units exhibited thermotropic liquid crystalline properties between 140°C and 230°C.

Synthesis and characterization of novel dibenz[a,c]anthracenedicarboxythioimides: the effect of thionation on self-assembly

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 78784-78790 ◽  
Author(s):  
Katie. M. Psutka ◽  
Kenneth E. Maly
Keyword(s):  
Self Assembly ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Crystalline Phases ◽  
Liquid Crystalline Phases ◽  
Self Association

The effect of thionation on the formation of columnar liquid crystalline phases of dibenzanthracenedicarboximides as well as their self-association in solution is described.

scholarly journals Synthesis and characterization of solid 2-methoxycinnamylidenepyruvic acid

2008 ◽  
Vol 33 (4) ◽  
pp. 61-68 ◽  
Author(s):  
C. T. de Carvalho ◽  
A. B. Siqueira ◽  
E. Y. Ionashiro ◽  
M. Pivatto ◽  
M. Ionashiro
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Molecular Geometry ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Purity Determination

The 2-methoxycinnamylidenepyruvic acid (2-MeO-HCP) was synthesized and characterized for nuclear magnetic resonance (¹H and 13C NMR), mass spectrometry (MS), Infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The application of DSC for purity determination is well documented in literature and is used in the analysis of pure organic compounds. The molecular geometry and vibrational frequencies of 2-MeO-HCP have been calculated.

Study of the Liquid Crystalline Phases in Some Compounds of 4-Trans-(4-Alkyl)Cyclo-Hexylphenyl-Alkylcarboxylate

1983 ◽  
Vol 38 (12) ◽  
pp. 1362-1364 ◽  
Author(s):  
I. H. Ibrahim ◽  
W. Haase
Keyword(s):  
Differential Scanning Calorimetry ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Intermolecular Distance ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Enthalpy Changes ◽  
Liquid Crystalline Phases ◽  
Nematic Phases

Abstract Three mesogenic compounds of the general formula have been investigated by differential scanning calorimetry. thermal optical microscopy and X-ray diffraction methods/Enthalpy changes of The different phase transitions for these compounds have been determined. H33 exhibits smectic B and nematic phases, whereas H34 and H75 exhibit only smectic B phases. The thickness of the smectic layers and the average intermolecular distance have been evaluated, as well as the corresponding molecular parameters in the nematic phase.

The synthesis and characterization of liquid crystalline oligoimides and polyimides

1995 ◽  
Vol 7 (4) ◽  
pp. 421-431 ◽  
Author(s):  
P Alder ◽  
J G Dolden ◽  
P Smith
Keyword(s):  
Liquid Crystalline ◽  
Solution Method ◽  
Molar Mass ◽  
Building Blocks ◽  
Decomposition Temperature ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Nematic Phases ◽  
Optical Polarizing Microscopy

There are few examples of thermotropic polyimides reported in the literature. In the present article the authors report the synthesis and characterization of some novel oligoand poly-imides which exhibit mesogenic behaviour. The solution method of Yamazaki et al (Yamazaki N, Higashi F and Kawasaki J 1974 J. Polym. Sci., Polym. Chem. Ed. 12 2149) for the preparation of polyamides was successfully applied to the formation of imide compounds and oligomers. Liquid crystal phases were characterized by optical polarizing microscopy and by differential scanning calorimetry. Two anhydrides were employed which were considered to be suitable building blocks for preparing potentially mesogenic polyimides, namely biphenyl tetracarboxytic dianhydride and pyromellitic dianhydride. Low-molar-mass materials were first synthesized with monoanhydride units to endcap the chains. using nadic and maleic anhydrides. Nematic phases Awere observed in several nadic diimide compounds containing multicyclic cores and in some low-molar-mass diimides and polyimides which contained a biphenylene unit in conjunction with at least one other unsaturated ring When the nadlmldes were heated above 220 C cross-linking and decomposition occurred with loss of mesogenic properties. A fusible polyimide was synthesized containing a flexible chain which exhibited thermotropic behaviour below its decomposition temperature.

A new family of bent-core C2-symmetric liquid crystals

2010 ◽  
Vol 88 (7) ◽  
pp. 639-645 ◽  
Author(s):  
Kyle A. Hope-Ross ◽  
Paul A. Heiney ◽  
John F. Kadla
Keyword(s):  
Differential Scanning Calorimetry ◽  
Small Angle ◽  
Liquid Crystalline ◽  
Side Chains ◽  
Scanning Calorimetry ◽  
X Ray ◽  
New Family ◽  
X Ray Scattering ◽  
Factors Influencing ◽  
Liquid Crystalline Phases

A series of C2-symmetric compounds with different core sizes and varying lengths and numbers of alkoxy side chains were prepared, and the factors influencing their liquid crystalline mesophase behaviour were investigated. The compounds studied were based on benzophenone, dibenzylidene-acetone, and 1,9-diphenyl-nona-1,3,6,8-tetraen-5-one cores with either 1 or 2 linear alkoxy side chains. The side chains were varied in length from C6H13 to C12H25. The liquid crystalline mesophase behaviour of the compounds was investigated using differential scanning calorimetry, polarizing optical microscopy, and small-angle X-ray scattering (SAXS). It was found that a number of the molecules were able to self-assemble into smectic and nematic liquid crystalline phases.

Synthesis and Characterization of Smectic Polymorphism in Higher Homologues of N-(p-n-Alkoxybenzylidene)-p-n-(Alkylanilines)

2003 ◽  
Vol 58 (2-3) ◽  
pp. 103-108 ◽  
Author(s):  
Venkata G. K. M. Pisipati ◽  
A. K. George ◽  
Ch. Srinivasu ◽  
P. N. Murty
Keyword(s):  
Differential Scanning Calorimetry ◽  
Alkyl Chain ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Phase Variants ◽  
Miscibility Studies

Higher homologues of N-(p-n-alkoxybenzylidene)-p-n-alkylanilines (nO.m) compounds with n = 15 and 18 and m = 4 to 10, 12, 14, and 16 have been synthesized and the smectic polymesomorphism is studied. The transition temperatures were obtained both from thermal polarizing microscopy and differential scanning calorimetry. The compounds exhibit a smectic-F phase from the isotropic melt, their amount increasing with the number of the alkoxy chain. This implies that with the alkoxy chain number the manifestation of smectic-F occurs with shorter alkyl chain. The phase variants were confirmed with miscibility studies

Sign in / Sign up

Export Citation Format

Share Document