Novel liquid-crystalline polymeric materials via noncovalent "grafting"

1992 ◽  
Vol 4 (5) ◽  
pp. 970-972 ◽  
Author(s):  
C. Geraldine Bazuin ◽  
Frank A. Brandys
Keyword(s):  
Liquid Crystalline ◽  
Polymeric Materials

scholarly journals Synthesis and Characterization of Certain Photoactive Liquid Crystalline Poly(ester amides) from 2,5-Pyridine Dicarboxylic Acid

2019 ◽  
Vol 31 (5) ◽  
pp. 997-1001
Author(s):  
V. Chitra ◽  
D. Roopsingh
Keyword(s):  
Dicarboxylic Acid ◽  
Liquid Crystalline ◽  
Uv Light ◽  
Polymeric Materials ◽  
Gel Permeation Chromatography ◽  
Information Storage ◽  
Storage Devices ◽  
Polarized Microscopy ◽  
Pyridine Dicarboxylic Acid ◽  
Optical Information Storage

A new series of four photo-crosslinkable thermotropic liquid crystalline poly(ester amides) were synthesized by direct polycondensation of 2,5-pyridine dicarboxylic acid with two different varying diols and diamines. Two diamines employed in the synthesis were 4,4′-diaminodiphenyl methane and 1,4-diaminobenzene. The arylidene diols 2,5-bis(4-hydroxy-3-methoxybenzylidene)cyclopentanone and 2,6-bis(4-hydroxy-3-methoxybenzylidene)cyclohexanone were also used. The synthesized poly(ester amides) were characterized by qualitative solubility test, FT-IR, 1H and 13C NMR spectra. The monomeric moieties were found to be well incorporated in the polymer back bone. The molecular weight of the polymer was assessed by gel permeation chromatography (GPC). The thermal phase transition behavior and liquid crystallinity of the poly(ester amides) were investigated by differential thermogravimetry (DTG) and hot stage optical polarized microscopy (HOPM), respectively. Interestingly, these poly(ester amides) in dimethylacetamide were found to possess photo-crosslinking characteristics when irradiated by UV light. These polymeric materials may find utility value in optical information storage devices.

The Processing of LC Thermosets in Orienting External Fields

1996 ◽  
Vol 425 ◽  
Author(s):  
Hilmar Körner ◽  
Atsushi Shiota ◽  
Christopher K. Ober
Keyword(s):  
Liquid Crystals ◽  
Data Storage ◽  
Liquid Crystalline ◽  
Polymeric Materials ◽  
Optical Filters ◽  
Mechanical Anisotropy ◽  
Molecular Organization ◽  
External Fields ◽  
Wide Range ◽  
Structural Applications

Liquid crystals may possess macroscopically aligned structural, electrical and optical properties when oriented in external fields which leads to a wide range of applications including optical filters, displays, and data storage devices. Combining the properties of thermosets [1, 2] with the properties of liquid crystals (LC) is a logical step towards creating new materials. The development of liquid crystalline thermosets (LCT) has been motivated by their potential use in structural applications and the need for more adaptable polymeric materials with tunable strength and stiffness as well as tailored mechanical anisotropy. It is known that mechanical properties of conventional thermosets are determined by many factors including curing agent, filler, degree of cure, crosslink density, glass transition temperature, and accelerator. In LCT's all of these factors will ultimately be controlled by the both the molecular organization and orientation of the LC phase.

Use of noncovalent interactions to form novel liquid crystalline polymeric materials

1994 ◽  
Vol 84 (1) ◽  
pp. 183-196 ◽  
Author(s):  
C. Geraldine Bazuin ◽  
Frank A. Brandys ◽  
Tegan M. Eve ◽  
Michel Plante
Keyword(s):  
Liquid Crystalline ◽  
Noncovalent Interactions ◽  
Polymeric Materials

Rheology and Processing of Polymeric Materials: Volume 1: Polymer Rheology

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Polymer Blends ◽  
Liquid Crystalline ◽  
Deformable Body ◽  
Continuum Theory ◽  
Polymeric Materials ◽  
Immiscible Polymer Blends ◽  
Filled Polymers ◽  
Crystalline Polymers ◽  
Polymeric Liquids ◽  
Molten Polymers

Volume 1 presents first fundamental principles of the rheology of polymeric fluid including kinematics and stresses of a deformable body, the continuum theory for the viscoelasticity of flexible homogeneous polymeric liquids, the molecular theory for the viscoelasticity of flexible homogeneous polymeric liquids, and the experimental methods for the measurement of the rheological properties of poylmeric liquids. The materials presented are intended to set a stage for the subsequent chapters by introducing the basic concepts and principles of rheology, from both phenomenological and molecular perspectives, ofstructurally simple flexible and homogeneous polymeric liquids. Next, this volume presents the rheological behavior of structurally complex polymeric materials including miscible polymer blends, block copolymers, liquid-crystalline polymers, thermoplastic polyurethanes, immiscible polymer blends, perticulare-filled polymers, organoclay nanocomposites, molten polymers with dissolved gas, and thermosts.

X-Ray Microscopy Of Multiphase Polymeric Materials

1996 ◽  
Vol 437 ◽  
Author(s):  
H. Ade ◽  
A. P. Smith ◽  
G. R. Zhuang ◽  
B. Wood ◽  
I. Plotzker ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
National Laboratory ◽  
Polymeric Materials ◽  
High Energy ◽  
Brookhaven National Laboratory ◽  
Energy Calibration ◽  
High Energy Resolution ◽  
X Ray ◽  
Scanning Transmission ◽  
Spectral Fidelity

AbstractWe have utilized the scanning transmission x-ray microscope at Brookhaven National Laboratory to acquire high energy resolution spectra of various polymers and to investigate the bulk characteristics of multiphasic polymeric materials with chemical sensitivity at a spatial resolution of about 50 nm. We present studies ranging from phase separated liquid crystalline polyesters and polyurethanes to various polymer blends. Improvements in the NEXAFS imaging and spectral acquisition protocol in the recent past provide much improved spectral fidelity and include in situ energy calibration with CO2.

Advances in microscopy of polymers: A FESEM and STM study

1991 ◽  
Vol 49 ◽  
pp. 1042-1043
Author(s):  
R.T. Chen ◽  
M.G. Jamieson
Keyword(s):  
Field Emission ◽  
Liquid Crystalline ◽  
Low Voltage ◽  
Polymeric Materials ◽  
Crystalline Polymer ◽  
Scanning Tunneling ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Techniques

Microscopy has played a major role in establishing structure-process-property relationships in the research and development of polymeric materials. With advances in electron microscopy instrumentation (e.g., field emission SEM - FESEM) and the invention of new scanning probe microscopes (e.g., scanning tunneling microscope - STM), resolution of structures or morphologies down to the nanometer scale can be achieved with ease. This paper will focus on the application of FESEM and STM in order to understand the structure of commercial polymeric materials. Characterization of polymers using other microscopy techniques such as TEM, thermal optical microscopy and atomic force microscopy (AFM) will also be discussed.The polymeric materials evaluated in this study include membranes, liquid crystalline polymer (LCP) fibers, multiphase polymer blends and polymer films or coatings. In order to minimize beam damage and maximize contrast for surface detail in beam sensitive polymers, low voltage SEM (LVSEM) was performed on a JEOL 840F field emission SEM.

Influence of Perfluoroarene-Arene Interactions on the Phase Behavior of Liquid Crystalline and Polymeric Materials

1999 ◽  
Vol 38 (18) ◽  
pp. 2741-2745 ◽  
Author(s):  
Marcus Weck ◽  
Alex R. Dunn ◽  
Kozo Matsumoto ◽  
Geoffrey W. Coates ◽  
Emil B. Lobkovsky ◽  
...  
Keyword(s):  
Phase Behavior ◽  
Liquid Crystalline ◽  
Polymeric Materials

Vibrational Spectroscopy of Certain Polymaleic- and Polyacrylic-Based Mesomorphic Polymers

1995 ◽  
Vol 49 (9) ◽  
pp. 1311-1316 ◽  
Author(s):  
Dimitris Tsiourvas ◽  
Constantinos M. Paleos ◽  
Jane Anastassopoulou ◽  
Theophile Theophanides
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Liquid Crystalline ◽  
Polymeric Materials ◽  
Intramolecular Hydrogen Bonding ◽  
Polar Group ◽  
Smectic Phases ◽  
Carboxylic Groups ◽  
Ft Ir ◽  
Intramolecular Hydrogen

The FT-IR/ATR technique has been employed in the investigation of the forces leading to the organization of a number of polymeric materials exhibiting thermotropic liquid crystalline character. Two types of compounds have been studied, i.e., one bearing the carboxylic polar group near the main chain and the other at the end of the side chain. Intermolecular and intramolecular hydrogen bonding between the carboxylic groups was found to lead to the formation of “facing” and “sideways” structures. Enhanced stability of these supramolecular structures was obtained by the presence of intramolecular hydrogen bonds between the amide groups, resulting in the formation of smectic phases. Furthermore, it has been found that the strengthening of hydrogen bonding between carboxylic groups is associated with a weakening of hydrogen bonds between the amide groups.

Sign in / Sign up

Export Citation Format

Share Document