Thermal and Spectral Analysis of Novel Amide-Tethered Polymers from Poly(allylamine)

2016 ◽  
Vol 69 (4) ◽  
pp. 458
Author(s):  
Paolo N. Grenga ◽  
Matthew J. Nethercott ◽  
Ayeisca E. Mateo ◽  
Mathew Patenaude ◽  
Todd Hoare ◽  
...  
Keyword(s):  
Solid State Nmr ◽  
Differential Scanning Calorimetry Analysis ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Multilayer Systems ◽  
Amide Linkage ◽  
Structure Property Relationships ◽  
Modified Polymers ◽  
Tethered Polymers ◽  
Allylamine Hydrochloride

Post-polymerization modification of poly(allylamine hydrochloride) was applied to synthesize a library of amide-linked polyelectrolytes with tethered aliphatic, aromatic, and cubyl moieties. The efficacy of amidation was determined to be between 12 and 98 %, depending on the electronics, sterics, and solubility of the amide linkage. 13C solid-state NMR was used to further validate their structure. Thermogravimetric analysis and differential scanning calorimetry analysis indicated that none of the new polymers displayed a classic melt/freeze profile, but all displayed onset decomposition temperatures smaller than 215°C. We anticipate that the structure–property relationships observed in the resulting library of graft-modified polymers can facilitate better understanding of how to design polyelectrolytes for the construction of well-defined multilayer systems.

Synthesis and Liquid Crystalline Properties of New Chiral Monomers and Polysiloxanes

2013 ◽  
Vol 815 ◽  
pp. 747-751
Author(s):  
Jian She Hu ◽  
Yi Nan Liu ◽  
Ya Ting Song ◽  
Di Wang
Keyword(s):  
Liquid Crystalline ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Cholesteric Phase ◽  
Crystalline Materials ◽  
H Nmr ◽  
Structure Property Relationships ◽  
Potential Applications ◽  
Liquid Crystalline Materials

To study the structure-property relationships of new chiral liquid crystalline materials based on menthol and explore their potential applications, a monomer 4-(4-allyloxybenzoyloxy) phenyl-4-menthyl-oxyacetyloxybiphenyl-4-carboxylate (LCM) and the corresponding homopolymer (LCP) were synthesized. The chemical structure was characterized by FT-IR and 1H NMR. The liquid crystalline properties were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction. The monomer LCM formed a cholesteric phase when a flexible linkage chain was inserted between the mesogenic core and the terminal menthyl groups by reducing the steric effect. The homopolymer LCP exhibited a batonnet texture of a smectic A phase.

scholarly journals Characterization of Composition and Structure–Property Relationships of Commercial Post-Consumer Polyethylene and Polypropylene Recyclates

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1574
Author(s):  
Markus Gall ◽  
Paul J. Freudenthaler ◽  
Joerg Fischer ◽  
Reinhold W. Lang
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Charpy Impact ◽  
Impact Testing ◽  
Gravimetric Analysis ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Melt Flow Rate ◽  
Impact Performance ◽  
Structure Property Relationships ◽  
Composition And Structure

The current efforts in moving closer towards a circular plastics economy puts massive pressure on recycled plastics, especially recycled polyethylene (rPE) and recycled polypropylene (rPP) to enter new markets. Their market penetration remained low so far, despite PE and PP constituting the largest share of plastic wastes. However, with the current imperative of more circularity comes a new focus on performance of recyclates. Hence, a detailed understanding of composition and structure–property relationships of post-consumer recyclates has to be developed. Five recycling companies from the Austrian and German markets were asked to supply their purest high-quality rPE and rPP grades. These were characterized by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), and Fourier-transform infrared (FTIR) spectroscopy, and micro-imaging. Technological characterization included density measurements, determination of the melt flow rate (MFR), and Charpy impact testing. All recyclates contained diverse contaminants and inclusions ranging from legacy fillers like calcium carbonate to polymeric contaminants like polyamides or polyolefin cross-contamination. The overall amount, size, and distribution of contaminants varied significantly among suppliers. Furthermore, first structure–property relationships for polyolefin recyclates that link inorganic content and polymeric purity with density and impact performance could be derived.

scholarly journals Significance of Theoretical Decomposition Enthalpies for Predicting Thermal Hazards

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Didier Mathieu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Nitroaromatic Compounds ◽  
Present Approach ◽  
Quantitative Structure ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Thermal Hazards ◽  
Structure Property Relationships ◽  
Quantitative Structure Property Relationships ◽  
Decomposition Enthalpy

Much effort is currently put into the development of models for predicting decomposition enthalpies measured using differential scanning calorimetry (DSC). As an alternative to the purely empirical schemes reported so far, this work relies on theoretical values obtained on the basis of simple assumptions. For nitroaromatic compounds (NACs) studied in sealed sample cells, our approach proves clearly superior to previous ones. In contrast, it correlates poorly with data measured in pin-hole sample cells. Progress might be obtained through a combination of the present approach with the usual Quantitative Structure-Property Relationships (QSPR) methodologies. This work emphasizes the significance of the theoretical decomposition enthalpy as a fundamental descriptor for the prediction of DSC values. In fact, the theoretical value provides a valuable criterion to characterize thermal hazards, as a complement to experimental decomposition temperatures.

Preparation of poly(ether ketone)s having phenyl, biphenyl, and terphenyl side groups and comparison of their properties

2016 ◽  
Vol 30 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Satoshi Kawaguchi ◽  
Atsushi Morikawa
Keyword(s):  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Side Group ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Property Relationships ◽  
Linear Poly ◽  
Ether Ketone

Three kinds of bis(aromatic fluoride) compounds, 3,5-bis(4-fluorobenzoyl)biphenyl (1), 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″-terphenyl (2), and 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″:4″,1′′′-quaterphenyl (3), were synthesized by cross-coupling of the corresponding triflates with phenylboronic acid. Linear poly(ether ketone)s (1x, 2x, and 3x) having phenyl, biphenyl, and terphenyl side groups, respectively, were prepared by the polycondensation of the bis(aromatic fluoride) compounds with bisphenol A (a) and 4,4′-dihydroxybiphenyl (b) in N-methyl-2-pyrrolidone. The obtained poly(ether ketone)s were characterized by X-ray diffraction, differential scanning calorimetry, and thermogravimetry. The structure–property relationships of these poly(ether ketone)s were examined and compared with those of poly(ether ketone)s (4x) having no side group, which were prepared from 3,5-bis(4-fluorobenzoyl)benzene (4). The properties of the poly(ether ketone)s, solubilities, and thermal properties were compared and discussed based on the length of the side groups.

scholarly journals Synthesis, liquid crystalline behaviour and structure–property relationships of 1,3-bis(5-substituted-1,3,4-oxadiazol-2-yl)benzenes

2020 ◽  
Vol 16 ◽  
pp. 149-158
Author(s):  
Afef Mabrouki ◽  
Malek Fouzai ◽  
Armand Soldera ◽  
Abdelkader Kriaa ◽  
Ahmed Hedhli
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystalline ◽  
Dipole Moments ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Rigid Core ◽  
X Ray ◽  
Structure Property Relationships ◽  
Crystal Properties

Two series containing 1,3-bis(1,3,4-oxadiazol-2-yl)benzene as a rigid core (RC) and alkyl or perfluoroalkyl as terminal chains were synthesized and characterized. Liquid crystal properties of the synthesized compounds have been investigated by polarizing optical microscopy, differential scanning calorimetry and X-ray diffraction techniques. Conformation effects of the synthesized products on the dipole moments were also investigated.

scholarly journals Laterally substituted symmetric and nonsymmetric salicylideneimine-based bent-core mesogens

2012 ◽  
Vol 8 ◽  
pp. 129-154 ◽  
Author(s):  
Sonja Findeisen-Tandel ◽  
Wolfgang Weissflog ◽  
Ute Baumeister ◽  
Gerhard Pelzl ◽  
H N Shreenivasa Murthy ◽  
...  
Keyword(s):  
Physical Properties ◽  
Liquid Crystalline ◽  
Optical Measurements ◽  
Disruptive Effect ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Structure Property Relationships ◽  
New Findings ◽  
Phenyl Rings ◽  
Intramolecular Hydrogen

Bent-core mesogens have gained considerable importance due to their ability to form new mesophases with unusual properties. Relationships between the chemical structure of bent-core molecules and the type and physical properties of the formed mesophases are relatively unknown in detail and differ strongly from those known for calamitic liquid crystals. In this paper symmetric and nonsymmetric five-ring salicylideneaniline-based bent-core mesogens are presented, and the effect of lateral substituents attached at the outer phenyl rings (F, Cl, Br) or the central phenyl ring (CH3) on the liquid-crystalline behaviour and on the physical properties is studied. Corresponding benzylideneaniline-based compounds were additionally prepared in order to study the influence of the intramolecular hydrogen bond. The occurring mesophases were investigated by differential scanning calorimetry, polarising microscopy, X-ray diffraction and dielectric and electro-optical measurements. The paper reports on new findings with respect to the structure–property relationships of bent-core mesogens. On one hand, the disruptive effect of laterally substituted halogen atoms, F, Cl and Br, on the mesophase behaviour of three isomeric series was much lower than expected. On the other hand, an increase of the clearing temperature by 34 K was observed, caused by small lateral substituents. The electro-optical behaviour, especially the type of polar switching and corresponding molecular movements, is sensitive to variations in the molecular structure.

scholarly journals Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

2017 ◽  
Vol 13 ◽  
pp. 2374-2384 ◽  
Author(s):  
Jan Podlesný ◽  
Lenka Dokládalová ◽  
Oldřich Pytela ◽  
Adam Urbanec ◽  
Milan Klikar ◽  
...  
Keyword(s):  
Emission Spectra ◽  
Coupling Reactions ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Third Order ◽  
Third Harmonic ◽  
Fundamental Properties ◽  
Cross Coupling Reactions ◽  
Structure Property Relationships ◽  
Target Molecules

Nine new quadrupolar chromophores based on diketopyrrolopyrrole were designed and prepared by cross-coupling reactions. The property tuning has been achieved by structural variation of the peripheral substituents (donor) and enlargement of the π-system. Fundamental properties of target molecules were studied by differential scanning calorimetry, electrochemistry, and absorption and emission spectra. Nonlinear optical properties were studied by measuring the third harmonic generation. The experimental data were completed by quantum-chemical calculations and structure–property relationships were elucidated.

scholarly journals Synthesis, characterization and structure-property relationships of 1,3-bis(5-substituted-1,3,4-oxadiazol-2-yl)benzenes

2019 ◽  
Author(s):  
Afef Mabrouki ◽  
Malek Fouzai ◽  
Armand Soldera ◽  
Abdelkader Kriaa ◽  
ahmed hedhli
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Dipole Moments ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Rigid Core ◽  
X Ray ◽  
Structure Property Relationships ◽  
Crystal Properties

Two series containing 1,3-bis(1,3,4-oxadiazol-2-yl)benzene as a rigid core (RC) and alkyl or perfluoroalkyl as terminal chains were synthesized and characterized. Liquid Crystal properties of the synthesized compounds have been investigated by Polarizing Optical Microscopy, Differential Scanning Calorimetry and X-ray Diffraction techniques. Conformation effects of the synthesized products on the dipole moments were also investigated.

Sign in / Sign up

Export Citation Format

Share Document