X-ray diffraction by thermotropic main-chain polymers with side groups. I. rigid polyesters

Two new samples of poly(amide-imide)-montmorillonite reinforced nanocomposites containing N-trimellitylimido-L-valine moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 5 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N-trimellitylimido-L-valine (3) with 4,4′-diaminodiphenyl ether 4 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PA-nanocomposite films (5a) and (5b) with 10 and 20 % silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposite films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.

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Synthesis of Polyazobenzenes Exhibiting Photoisomerization and Liquid Crystallinity

Polymers ◽

10.3390/polym11020348 ◽

2019 ◽

Vol 11 (2) ◽

pp. 348 ◽

Cited By ~ 2

Author(s):

Masashi Otaki ◽

Reiji Kumai ◽

Hajime Sagayama ◽

Hiromasa Goto

Keyword(s):

Conjugated Polymers ◽

Main Chain ◽

Cross Coupling ◽

Industrial Applications ◽

Optical Absorption Spectroscopy ◽

X Ray Diffraction ◽

Liquid Crystallinity ◽

X Ray ◽

Cis And Trans ◽

Chain Type

While only a few studies have investigated the synthesis of main chain-type polyazobenzenes, they continue to draw an increasing amount of attention owing to their industrial applications in holography, dyes, and functional adhesives. In this study, dibromoazobenzene was prepared as a monomer for constructing azo-based π-conjugated polymers. Miyaura–Suzuki cross-coupling polymerization was conducted to develop copolymers containing an azobenzene unit as a photoisomerization block and a pyrimidine-based liquid crystal generator block. The prepared polymers exhibited thermotropic liquid crystallinity and underwent cis and trans photoisomerization upon irradiation with ultraviolet and visible light. Furthermore, the photoisomerization behavior was examined using optical absorption spectroscopy and synchrotron X-ray diffraction spectrometry.

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Chiral Liquid Crystalline Polymers Containing Isosorbide Groups

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.781-784.403 ◽

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.

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Synthesis and properties of new polyamide-organoclay nanocomposites containing pyrazine moiety in the main chain

Science and Engineering of Composite Materials ◽

10.1515/secm-2011-0105 ◽

2012 ◽

Vol 19 (3) ◽

pp. 215-220

Author(s):

Khalil Faghihi ◽

Mohammad Naderi-Ghomi ◽

Mohsen Hajibeygi

Keyword(s):

Main Chain ◽

Nanocomposite Films ◽

Triphenyl Phosphite ◽

Direct Polycondensation ◽

Polycondensation Reaction ◽

X Ray Diffraction ◽

Solution Intercalation ◽

X Ray ◽

Diaminodiphenyl Sulfone ◽

Thermal Stability Of

AbstractA series of polyamide (PA)/montmorillonite nanocomposites containing pyrazine moiety in the main chain were synthesized by a convenient solution intercalation technique. PA 3 as a source of polymer matrix was synthesized by the direct polycondensation reaction of pyrazine-2,3-dicarboxylic acid 1 with 4,4′-diaminodiphenyl sulfone 2 in the presence of triphenyl phosphite, CaCl2, pyridine, and N-methyl-2-pyrrolidone. The resulting nanocomposite films were characterized by Fourier transform infrared spectra, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis (TGA). The results showed that organo-modified clay was dispersed homogeneously in the PA matrix. TGA indicated an enhancement of thermal stability of new nanocomposites compared with the pure polymer.

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Synthesis and Characterization of New Polyimide/Organoclay Nanocomposites Containing Benzophenone Moieties in the Main Chain

Journal of the Mexican Chemical Society ◽

10.29356/jmcs.v57i2.225 ◽

2017 ◽

Vol 57 (2) ◽

Cited By ~ 1

Author(s):

Khalil Faghihi ◽

Mostafa Ashouri ◽

Akram Feyzi

Keyword(s):

Main Chain ◽

In Situ Polymerization ◽

Clay Content ◽

Nanocomposite Films ◽

X Ray Diffraction ◽

X Ray ◽

Ft Ir ◽

Ft Ir Spectroscopy

<p>A series of nanocomposites consist of organic polyimide and organo-modified clay content varying from 0 to 5 wt%, were successfully prepared by in situ polymerization. Polyimide used as a matrix of nanocomposite was prepared through the reaction of 1,4-bis [4-aminophenoxy] butane (APB) and 3،3΄،4،4΄-benzophenone tetra carboxylic dianhydride (BTDA) in N,N-dimethylacetamide (DMAc). The resulting nanocomposite films were characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).</p>

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