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.

scholarly journals Synthesis and Characterization of Semicrystalline Polyimides Containing Bridged Linkages

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Min Chao
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
High Weight ◽  
Softening Temperature ◽  
Synthesis And Characterization ◽  
Excellent Thermal Stability

A series of polyimides (PI) containing bridged linkages were prepared successfully through a three-step technique. The results indicated that the glass transition temperature (Tg) of polyimides was affected by flexibility of polymer chain and the intermolecular interactions. ODPA-TPER-based polyimide possesses the lowest Tg, which was 214°C. All polyimides had semicrystalline characteristics, and ODPA-TPER-based PI exhibited the lowest melting temperature (Tm) at 316°C. The polyimides had high weight loss temperatures, which indicated that bridged linkages can reduce the softening temperature, meanwhile keeping excellent thermal stability.

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 novel benzoxazines containing nitrile and allyl groups and their polymers

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Hongchun Zhang ◽  
Zaijun Lu
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Ring Opening ◽  
Synthesis And Characterization ◽  
Curing Process ◽  
Oxazine Ring ◽  
Thermal Stability Of

AbstractA p-cyanophenol and allylamine based benzoxazine has been synthesized and characterized. This benzoxazine has nitrile and allyl functionalities that can polymerize, resulting in a highly crosslinked material. The DSC spectra of novel benzoxazine monomer reveal that incorporation of the nitrile and allyl group greatly decreases the ring-opening temperature of oxazine rings (140°C). The IR spectra of curing process indicate that the polymerization of oxazine ring accompany with the curing reaction of allyl and nitrile groups. Benzoxazine monomers with one or none of the two functionalities were also prepared to study structure effect on thermal properties of resulted polymer. The comparison of results confirms that introducing the two functionalities improved glass transition temperature (238 °C), thermal stability of polybenzoxazine (T5%=340 °C), and char yield (57%).

Synthesis and Characterization of Aromatic Polyimide Containing 3,6-Diamino-9-Alkylcarbazole and Aromatic Tetracarboxylic Dianhydrides

2001 ◽  
Vol 13 (4) ◽  
pp. 281-286 ◽  
Author(s):  
Shinji Watanabe ◽  
Taizoh Yamamoto ◽  
Miki Murata ◽  
Yuzuru Masuda
Keyword(s):  
Weight Loss ◽  
Glass Transition ◽  
Organic Solvents ◽  
Ring Opening ◽  
Synthesis And Characterization ◽  
Step Method ◽  
Aromatic Polyimide ◽  
Glass Transition Temperatures ◽  
Alkyl Chains

New soluble polyimides with inherent viscosities of 0.25–0.62 dl g−1 were synthesized from 3,6-diamino-9-alkylcarbazole and various aromatic tetracarboxylic dianhydrides by the conventional two-step method, including ring-opening polyaddition and subsequent thermally cyclodehydration. Most of the polyimides having hexyl alkyl chains were soluble in N-methylpyrrolidinone and m-cresol, while the polymers having ethyl chains were not soluble in organic solvents. The glass transition temperatures and 10% weight loss temperatures under argon of the polyimides having hexyl chains were in the ranges 232–269 °C and 485–518 °C, respectively.

Synthesis and characterization of polyurethanes bearing carbosilane segments

RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 94803-94808
Author(s):  
Ayumu Karimata ◽  
Kozo Matsumoto ◽  
Takeshi Endo
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Synthesis And Characterization ◽  
And Storage ◽  
Lower Glass Transition Temperature

New polyurethanes bearing carbosilane segment (1a–c) were synthesized and found to exhibit lower glass transition temperature and storage moduli than corresponding reference polyurethanes 2a–c, while thermal stability was retained.

scholarly journals Design of an n-type low glass transition temperature radical polymer

2021 ◽  
Author(s):  
Teng Chi ◽  
Siddhartha Akkiraju ◽  
Zihao Liang ◽  
Ying Tan ◽  
Ho Joong Kim ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Synthesis And Characterization ◽  
Design Synthesis

We document the design, synthesis, and characterization of the first low glass transition temperature, n-type (i.e., preferentially-reduced) radical polymer.

scholarly journals Polarization and Piezoelectric Properties of a Nitrile Substituted Polyimide

1996 ◽  
Vol 459 ◽  
Author(s):  
Joycelyn Simpson ◽  
Zoubeida Ounaies ◽  
Catharine Fay
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Remanent Polarization ◽  
Piezoelectric Properties ◽  
Synthesis And Characterization

ABSTRACTThis research focuses on the synthesis and characterization of a piezoelectric (β-CN)-APB/ODPA polyimide. The remanent polarization and piezoelectric d31 and g33 coefficients are reported to assess the effect of synthesis variations. Each of the materials exhibits a level of piezoelectricity which increases with temperature. The remanent polarization is retained at temperatures close to the glass transition temperature of the polyimide.

Sign in / Sign up

Export Citation Format

Share Document