Synthesis and Characterization of New Photorefractive Polymers with High Glass Transition Temperatures

1998 ◽  
Vol 31 (18) ◽  
pp. 6184-6189 ◽  
Author(s):  
Martin Döbler ◽  
Christoph Weder ◽  
Peter Neuenschwander ◽  
Ulrich W. Suter ◽  
Stéphane Follonier ◽  
...  
Keyword(s):  
Glass Transition ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Photorefractive Polymers

scholarly journals Synthesis and characterization of semiaromatic polyamides comprising benzofurobenzofuran repeating units

2017 ◽  
Vol 8 (14) ◽  
pp. 2197-2209 ◽  
Author(s):  
Julien Cretenoud ◽  
Bilal Özen ◽  
Thomas Schmaltz ◽  
Daniel Görl ◽  
Alberto Fabrizio ◽  
...  
Keyword(s):  
Glass Transition ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Glass Transition Temperatures

Extended π-conjugated segments such as benzofurobenzofuran can be included into polyamides with high glass transition temperatures.

Naphthalene-based poly(aryl ether)s. II. Synthesis and characterization of poly(ether ketone)s containing two 1,4-naphthylene moieties in the repeat unit

1997 ◽  
Vol 75 (10) ◽  
pp. 1346-1353 ◽  
Author(s):  
Zhi Yuan Wang ◽  
Peter W. Broughton
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Repeat Unit ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Aryl Ether ◽  
Glass Transition Temperatures ◽  
Phenyl Sulfone ◽  
Ether Ketone

Two new monomers, 4-chloro-1-(4′-fluoro-1-naphthoyl)naphthalene and 1,4-bis(4′-fluoro-1′-naphthoyl)benzene, have been synthesized and polymerized with four different bisphenols to give two series of the naphthalene-based poly(ether ketone)s that are analogous to commercial PEEK and PEEKK. The effect of the introduction of one or two 1,4-naphthylene moieties, in the backbone of the repeat unit, on the glass transition temperatures has been studied. The glass transition temperatures usually increased by 20–45 °C upon replacing one 1,4-phenylene with one 1,4-naphthylene moiety. All new poly (ether ketone)s prepared in tetramethylene sulfone were amorphous, with the glass transition temperatures in a range of 212–273 °C. The polymer produced from 1,4-bis(4′-fluoro-1′-naphthoyl)benzene and 1,4-hydroquinone in phenyl sulfone as a solvent at 300 °C showed semicrystalline properties with a melting temperature of 310 °C. Keywords: naphthalene, poly(ether ketone)s, synthesis, characterization, glass transition temperature.

Synthesis and characterization of extended poly(phenylquinoxalines) containing carbonyl, ether and sulphide linking groups

1995 ◽  
Vol 7 (4) ◽  
pp. 481-492 ◽  
Author(s):  
Rajendra K Singh ◽  
Rooma Mago Mehta ◽  
R G Bass
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Glass Transition ◽  
Transition Temperature ◽  
Primary Objective ◽  
Synthesis And Characterization ◽  
Glass Transition Temperatures ◽  
Hydrocarbon Solvents ◽  
As Solubility

A series of eight novel extended poly(phenylquinoxalines) (PPQs) containing carbonyl, ether and sulphide linking groups were prepared by polycondensation of 4,4'-bis(phenylglyoxalyl-4-phenoxy-4'-benzoyl)diphenyl sulphide, I-D, and 4,4'-bis(phenyl glyoxalyl-4-phenylthio-4'-benzoyl)diphenyl sulphide, 2-D, with four aromatic bis(o-diamines) in m-cresol. The primary objective of this study was to correlate the effect of these linkages on the various properties such as solubility, thermal stability and glass transition temperature of the PPQs. Polymerization of 1-D was carried out in an oil bath maintained at 195-200C whereas polymerization of 2-D was performed at ambient temperature. The polymers prepared were soluble in m-cresol. dimethylsulphoxide, N,N-dimethylacetamide, I-methyl-2-pyrrolidinone and chlorinated hydrocarbon solvents, and formed tough transparent, yellow fingernail-creasable films from chloroform solutions. The inherent viscosities ranged between 0.44 and 0.96 dl g' '. The glass transition temperatures were nearly identical for both systems and ranged from 217-231 'C for polymers prepared from l-D and from 215-233"C for polymers prepared from 2-D. The PPQs having carbonyl and stJlphide linking groups had higher thermal stability in comparison to PPQs having carbonyl, ether and sulphide linkages. The temperature of 10% weight loss for I-D ranged from 484-496 'C in air and 485-516"C in helium whereas those for 2-D ranged from 538-579 XC in air and 522-549 in helium.

Side Chain Liquid Crystalline Block Copolymers With Chiral Smectic C* Mesogens

1996 ◽  
Vol 425 ◽  
Author(s):  
Wen Yue Zheng ◽  
Paula T. Hammond
Keyword(s):  
Glass Transition ◽  
Block Copolymers ◽  
Anionic Polymerization ◽  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Side Chain ◽  
Synthesis And Characterization ◽  
Glass Transition Temperatures ◽  
Smectic C

AbstractA new series of side chain liquid crystalline-amorphous diblock copolymers has been successfully synthesized using chiral mesogens. Anionic polymerization techniques have been used to make these monodisperse diblock materials. Preliminary studies suggest that these microphase segregated diblock copolymers exhibit a smectic C* phase. This mesophase exists between and above the glass transition temperatures of the two polymer blocks. Synthesis and characterization of these novel materials are discussed.

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