Glass transition temperature from the chemical structure of conjugated polymers

The comparative analysis of gas transport properties and conformational parameters of membranes obtained from two polyimides and polysulfone was made. It was shown that the introduction of a sulfone group instead of a methylene group in the amine component of polyimide leads to an increase in glass transition temperature and of polymer membrane permeability coefficient and a reduction in selectivity. Also it was demonstrated that the solvent used during the preparation of polymer membranes had a significant influence on their gas transport characteristics.

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Mapping Chemical Structure–Glass Transition Temperature Relationship through Artificial Intelligence

Macromolecules ◽

10.1021/acs.macromol.0c02594 ◽

2021 ◽

Vol 54 (4) ◽

pp. 1811-1817

Author(s):

Luis A. Miccio ◽

Gustavo A. Schwartz

Keyword(s):

Artificial Intelligence ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Chemical Structure ◽

Temperature Relationship

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Chemical structure and physical properties of cyclic olefin copolymers (IUPAC Technical Report)

Pure and Applied Chemistry ◽

10.1351/pac200577050801 ◽

2005 ◽

Vol 77 (5) ◽

pp. 801-814 ◽

Cited By ~ 102

Author(s):

Ju Young Shin ◽

Ji Yong Park ◽

Chenyang Liu ◽

Jiasong He ◽

Sung Chul Kim

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Chemical Structure ◽

Moisture Absorption ◽

High Surface ◽

Polymeric Materials ◽

Surface Characteristics ◽

Cyclic Olefin ◽

Cyclic Olefin Copolymers

Cyclic olefin copolymers comprise a new class of polymeric materials showing properties of high glass-transition temperature, optical clarity, low shrinkage, low moisture absorption, and low birefringence. There are several types of cyclic olefin copolymers based on different types of cyclic monomers and polymerization methods. In this work, we have analyzed the chemical structure of the currently commercialized cyclic olefin copolymers by 13C NMR, and investigated their glass-transition temperatures and surface characteristics. It was observed that the glass-transition temperature, Tg, of cyclic olefin copolymers depended on the bulkiness of the main chain, and the number of rings had an important role in increasing the bulkiness of cyclic olefin copolymers. Cyclic olefin copolymers with polar substituents such as ester or ether groups showed high surface energy per area and peel strength.

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Glass transition temperature and elastic modulusof nanocomposites based on polyimides

Vestnik MGSU ◽

10.22227/1997-0935.2015.6.50-63 ◽

2015 ◽

pp. 50-63

Author(s):

Tat’yana Anatol’evna Matseevich ◽

Marina Nikolaevna Popova ◽

Andrey Aleksandrovich Askadskiy

Keyword(s):

Mechanical Properties ◽

Glass Transition ◽

Elastic Modulus ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Chemical Structure ◽

Van Der Waals Volume ◽

Polar Groups ◽

Wide Range ◽

Nanoparticles Concentration

Today great attention is paid to production and research of the mechanical and termal properties of nanocomposites based on polyimides. These polymers are heatresisting and possess the increased mechanical properties in wide range of temperatures. Various nanoparticles are introduced into polyimides: graphite nanotubes and flatparticles, the particles of SiO , the surface of which is modified, the particles of ZrOandmontmorillonite, etc.The authors analyzed the influence of nanoparticles on the glass transition temper-ature T and elastic modulus E of the polyimides based on 1,3-bis-(3,3’,4,4’-dicarboxy-phenoxy)benzene and 4,4’-bis-(4-aminophenoxy)biphenyl, and pyromellitic dianhydride and oxydianiline. Nanoparticles introduced in small amounts are produced of graphite and ZrO . The suggested ratios take into account the chemical structure of the polymer and nanoparticles, as well as the structure of their surface in case of chemical modification; the concentration of nanoparticles and their form, the number of polar groups on the surface. The number of polar groups and nanoparticles’ concentration have the greatest influence on T . The elastic modulus of nanocomposites depending on nanoparticles’ concentration is connected with van der Waals volume of the repeating unit of polymer and nanoparticle.

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Study of Thermal Aging of Nadimide Polymer: Physicochemical Characterization of the Properties of the Crosslinked IP960 System

High Performance Polymers ◽

10.1088/0954-0083/8/4/007 ◽

1996 ◽

Vol 8 (4) ◽

pp. 579-598 ◽

Cited By ~ 3

Author(s):

J P Habas ◽

J Peyrelasse ◽

M F Grenier-Loustalot

Keyword(s):

Weight Loss ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Thermal Treatment ◽

Crosslink Density ◽

Chemical Structure ◽

Physicochemical Characterization ◽

Minimal Period

In order to evaluate the thermostability of the IP960 polymer, we have characterized the physicochemical properties of samples exposed at 295 °C for periods up to 3000 h. According to the time of thermal treatment, various phenomena occur such as an increase in glass transition temperature and crosslink density. After a minimal period of 200 h at 295 °C, the weight loss of samples is representative of the degradation of crosslinked IP950. Using FTIR, we have analysed the changes in the chemical structure of the polymer. We propose a mechanism which could explain the degradation of the crosslinked compound.

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