Physical Studies of A Series of Main-Chain Liquid Crystalline Polymers With Long Soft Segment

1993 ◽  
Vol 321 ◽  
Author(s):  
Bing Wu ◽  
C. Peter Lillya ◽  
Richard S. Stein
Keyword(s):  
Thermal Properties ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Soft Segment ◽  
Liquid Crystalline Polymers ◽  
Segment Length ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Crystalline Polymers ◽  
Segmented Copolymers

ABSTRACTA series of Main-chain liquid crystalline polymers with long and polydisperse soft segments has been synthesized. The thermal properties of these polymers have been characterized by differential scanning calorimetry, optical microscopy and wide angle X-ray diffraction. Unexpectedly, these polymers have a strong tendency to form purely smectic Mesophases. The degree of ordering of these polymeric mesophases is Much higher than that of the mesophase formed by a low molecular weight Model compound with the same Mesogen. The soft segment length effects on thermal behavior of such segmented copolymers have been elucidated. A semi-quantitative theory has been formulated to interpret these observations. A phase diagram relating thermal properties to soft segment length has been proposed.

Chiral Liquid Crystalline Polymers Containing Isosorbide Groups

2013 ◽  
Vol 781-784 ◽  
pp. 403-406
Author(s):  
Mei Tian ◽  
Zhi Xin Xu ◽  
Li Gao ◽  
Dan Shu Yao ◽  
Xiao Zhi He ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Liquid Crystalline Polymers ◽  
Optical Microscope ◽  
Liquid Crystal Polymers ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystalline Polymers

A series of new main-chain liquid-crystal polymers (LCPs) were prepared from sebacoyl chloride (SD) and various amount of 4, 4-Dihydroxy-2, 2-dimethyl Benzalazine (DDBA) and isosorbide (ISO). The liquid crystal (LC) properties were investigated by polarized optical microscope (POM), differential scanning calorimetry (DSC) and X-ray diffraction measurements. P1 exhibited a typical nematic thread texture, which contains no ISO. P2-P7 are Sc* and N LCPs, which exhibited broken fan-shaped texture and droplet texture. The introduction of chiral units into the polymers led to a change of mesomorphase, as compared with P1.

scholarly journals Main-chain liquid crystalline polymers bearing periodically grafted folding elements

2021 ◽  
Vol 12 (7) ◽  
pp. 1050-1059
Author(s):  
Gabriel Ogunsola Orodepo ◽  
E. Bhoje Gowd ◽  
S. Ramakrishnan
Keyword(s):  
Liquid Crystalline ◽  
Main Chain ◽  
Liquid Crystalline Polymers ◽  
Crystalline Polymers ◽  
Interesting Alternative

Inclusion of non-mesogenic pendant segments, such as alkyl, PEG and fluoroalkyl, at periodic intervals along the backbone of main-chain LCPs, that contain flexible spacers, provides an interesting alternative to control the mesophase structure and the layer periodicity.

Collective fluctuation in chiral smectic phases of main‐chain liquid crystalline polymers

2007 ◽  
Vol 34 (3) ◽  
pp. 305-310 ◽  
Author(s):  
Kazuyuki Hiraoka ◽  
Takuhei Nose ◽  
Yoshiko Uematsu ◽  
Masatoshi Tokita ◽  
Junji Watanabe
Keyword(s):  
Liquid Crystalline ◽  
Main Chain ◽  
Liquid Crystalline Polymers ◽  
Crystalline Polymers ◽  
Smectic Phases
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