scholarly journals Colorless Semi-Alicyclic Copolyimides with High Thermal Stability and Solubility

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1319 ◽  
Author(s):  
Zhongxu Lan ◽  
Chunyu Li ◽  
Yanlei Yu ◽  
Jia Wei
Keyword(s):  
Thermal Stability ◽  
Decomposition Temperature ◽  
High Thermal Stability ◽  
Thermal Decomposition Temperature ◽  
One Pot ◽  
Plastic Substrates ◽  
Good Solubility ◽  
Molecular Charge ◽  
Intra Molecular Charge Transfer ◽  
Solution Polycondensation

A series of colorless copolyimide films with high thermal stability and good solubility are synthesized from (trifluoromethyl)biphenyl-4,4’-diamine (TFMB) with different 1,2,4,5-cyclohexanetetracarboxylic dianhydride (HPMDA) to 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane (6FDA) dianhydride mole ratios through one-pot solution polycondensation. These copolyimide films exhibit excellent optical transparency (T400 > 90% and λ0 ~305–333 nm) with a thickness of 15 μm and good solubility in most organic solvents. The excellent optical properties are mainly attributed to the low inter- and intra-molecular charge transfer interactions due to the alicyclic structure and the strong electronegative CF3 groups. The glass transition temperature increases from 332 to 352 °C with increasing HPMDA content in the copolymers, while the thermal decomposition temperature is improved with increasing 6FDA content. These results indicate that the copolyimide films can be successfully utilized in the development of novel heat-resistant plastic substrates for the optoelectronic engineering applications.

scholarly journals Synthesis and electro-optical properties of fluorene containing blue luminescent rod-coil homopolymers with pendant pyridine

2017 ◽  
Vol 35 (1) ◽  
pp. 217-224
Author(s):  
Duryodhan Sahu ◽  
Subhendu Chakroborty
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Average Molecular Weight ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Decomposition Temperature ◽  
High Thermal Stability ◽  
Photoluminescence Spectra ◽  
Fluorescence Emission Spectra ◽  
Good Solubility

AbstractTwo well defined, blue luminescent homopolymers containing 9,9-diethylfluorene core with electron withdrawing pendant pyridine, Suzuki-coupled with the corresponding borolane of decoxy phenyl (PFPA) and naphthalene (PFNA) have been designed and synthesized efficiently. The obtained rod-coil polymers have the average molecular weight of 15212 (PFPA) and 15130 (PFNA) with polydispersity indices (PDIs) 1.07 and 1.3, respectively. The polymers have good solubility and high thermal stability with the decomposition temperature of 362 °C (PFPA) and 367 °C (PFNA) correspondingly. Furthermore the optical and electrochemical properties of the polymers have been investigated. The polymers exhibited photoluminescence (PL) maxima at 410 nm (PFPA) and 414 nm (PFNA) excited at 340 nm, as stable blue luminescence polymers at low concentration of 10−6 M with a quantum yield of 0.64 and 0.62, respectively. In addition the annealed (150 °C) polymer films showed better stability of its photoluminescence spectra. Absorbance and fluorescence emission spectra of PFPA and PFNA were compared in order to evaluate the effects of substituent, phenyl and naphthalene in pyridine pendant fluorene moieties.

Novel polyhydrazides and polyoxadiazoles based on 1,3,4‐thiadiazole moiety in the main chain with high thermal stability, good solubility, and notable antimicrobial activity

2019 ◽  
Vol 136 (28) ◽  
pp. 47770 ◽  
Author(s):  
Kamal I. Aly ◽  
Osama Younis ◽  
Nayef S. Al‐Muaikel ◽  
Ahmed A. Atalla ◽  
Abu‐Bakr A. A. M. El‐Adasy ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Antimicrobial Activity ◽  
Main Chain ◽  
High Thermal Stability ◽  
Good Solubility

Studies on Thermal Stability and Rheological Property of PU/PVDF Blend

2011 ◽  
Vol 311-313 ◽  
pp. 1065-1070
Author(s):  
Guo Lan Huan ◽  
Jian Li Liu ◽  
Qi Yun Du ◽  
Xiao Yu Hu
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Shear Stress ◽  
Rheological Property ◽  
Decomposition Temperature ◽  
Dynamic Equations ◽  
Thermal Decomposition Temperature ◽  
Thermal Stability Of ◽  
Decomposition Activation Energy

In this article, the thermal stability of PU/PVDF blend was investigated by thermogravimetry (TG), and their rheological property was studied through testing and analyzing the rheological curves. The results showed that, with the increase in PVDF content, the thermal decomposition temperature of PU/PVDF blend increased, and by fitting relevant data to thermal decomposition dynamic equations, it was found that thermal decomposition activation energy of the blend increased gradually, i.e. the thermal stability of the blend increased gradually. Meantime, based on the curves of shear stress vs. shear rate of the blend at 180°C and 200°C, it was shown that for PU/PVDF blend, with the decrease of temperature and the increase in PVDF content, the non-Newtonian index decreased, while the viscosity of the blend increased.

scholarly journals Promotion of poly(vinylidene fluoride) on thermal stability and rheological property of ethylene-tetrafluoroethylene copolymer

e-Polymers ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 541-549 ◽  
Author(s):  
Jing Qian ◽  
Chao Fu ◽  
Xianyou Wu ◽  
Xianghai Ran ◽  
Wei Nie
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Vinylidene Fluoride ◽  
Decomposition Temperature ◽  
Application Area ◽  
Thermal Decomposition Temperature ◽  
Rheological Measurements ◽  
Maximum Decomposition Rate ◽  
Poly Vinylidene Fluoride ◽  
Ethylene Tetrafluoroethylene

AbstractIn this work, the thermal stability, rheological properties and mechanical properties of ethylene-tetrafluoroethylene copolymer (ETFE)/poly(vinylidene fluoride) (PVDF) blends were investigated by thermogravimetric analysis, rheometer and the tensile test. Thermal results indicated that blends had better thermal oxidation resistance than pure ETFE. Particularly, the initial thermal decomposition temperature (Td0) and the temperature at maximum decomposition rate (Tdmax) of PVDF/ETFE (10/90 wt%) blends were at 374.49°C and 480°C, which were 52.6°C and 34°C higher than pure ETFE. The activation energy of thermal degradation (Ed) of ETFE was 66 kJ/mol, while the PVDF/ETFE (10/90 wt%) blends presented a higher Ed, near 187 kJ/mol. Furthermore, rheological measurements demonstrated that the shear-thinning tendency of blends became stronger with increasing PVDF content. PVDF/ETFE (10/90 wt%) blends had somewhat lower mechanical properties than ETFE, which was still high enough for various applications. Blends with PVDF provided an efficient method to extend the application area of ETFE.

Synthesis of Main-Chain Polyimides Containing Azoaryl and their Third-Order NLO Properties

2011 ◽  
Vol 306-307 ◽  
pp. 215-219
Author(s):  
Jie Ping Shi ◽  
Li Wei ◽  
Hong Wen Hu ◽  
Ting Chao He ◽  
Xiao Qiang Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Main Chain ◽  
High Thermal Stability ◽  
Azo Compounds ◽  
Third Order ◽  
Nlo Properties ◽  
The Third ◽  
Good Solubility ◽  
Azo Group ◽  
532 Nm

A series of main-chain polyimides containing azo aryl with different substituted groups have been synthesized by a condensation of corresponding N,N-dichloroethylaminoaryl azo compounds with 4,4’-(hexafluoroisopropylidene) diphthalic bis-imide in an alkaline DMF solution, which have high thermal stability and good solubility in organic solvents. The third-order NLO measurements made with Z-scan technique at 532 nm indicate that the polyimides containing p-nitrophenylazo and nitrobenzothiazole azo group (P2 and P3) have larger third-order nonlinear absorption coefficient (ß) and the nonlinear refractive coefficient (n2).

Synthesis and characterization of novel fluorinated polybenzoxazoles derived from 2,5-difluoroterephthalic acid

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiao-Song Huang ◽  
Feng-Ling Qing
Keyword(s):  
Thermal Stability ◽  
Organic Solvents ◽  
Terephthalic Acid ◽  
Polyphosphoric Acid ◽  
Synthesis And Characterization ◽  
One Pot ◽  
Good Solubility ◽  
The One ◽  
Thermal Stability Of

AbstractA new serious of fluorinated polybenzoxazoles (PBOs) were prepared from 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane together with 2,5- difluoroterephthalic acid (DFTA) and terephthalic acid by the one-pot polycondensation in polyphosphoric acid. The resulting PBOs showed good solubility in many common organic solvents and the thermal stability of PBOs was improved by the introduction of DFTA monomer.

Lanthanide(III) complex metal-organic frameworks with a phenanthroline-carboxylate derivate and 2,5-thiophenedicarboxylate coligand: hydrothermal synthesis, crystal structure, and high thermostability

2018 ◽  
Vol 73 (5) ◽  
pp. 311-317
Author(s):  
Zhao Xu ◽  
Fengqin An ◽  
Xiaohui Ma ◽  
Huiliang Zhou ◽  
Weiming Song ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Metal Organic Frameworks ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
3D Networks ◽  
Point Symbol

AbstractBased on 2-(4-carboxyphenyl)imidazo[4,5-f]-1,10-phenanthroline (HNCP) and 2,5-thiophenedicarboxylate (TDC2−) ligands, three new lanthanide-containing (Sm, Nd, and Pr) compounds, [Sm(NCP)(TDC)]n (1), [Nd(NCP)(TDC)]n·2n(H2O)0.5 (2), and [Pr(NCP)(TDC)]n·n(H2O)0.5 (3), have been synthesized using the hydrothermal method and structurally characterized using single-crystal X-ray diffraction. Structural analyses have revealed that compounds 1–3 are 3D isostructural metal-organic frameworks in which the [Ln2(COO)4] dimers can be regarded as 6-connecting nodes, and the TDC2− and NCP− ligands are simplified as connectors to achieve the double interspersed 3D networks with the point symbol {412·63}. Thermogravimetric analysis has illustrated that the rigid architecture contributes to superior thermal stability with a thermal decomposition temperature of more than 400°C for the resulting metal-organic frameworks.

Synthesis of a metal-coordinated N-substituted polybenzimidazole pyridine sulfone and method for the nondestructive analysis of thermal stability

2018 ◽  
Vol 31 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Peng Yang ◽  
Li Yang ◽  
Junxiao Yang ◽  
Xuan Luo ◽  
Guanjun Chang
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
High Performance ◽  
Decomposition Temperature ◽  
Metal Coordination ◽  
Thermal Decomposition Temperature ◽  
Quenching Effect ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Performance Functional

N-substituted metal-coordinated cross-linking polybenzimidazole pyridine sulfone, as novel class of high-performance functional polymers, has been obtained by the coordination of N-substituted polybenzimidazole pyridine sulfone (Py-N-PBIS) ligand with varying content of metallic ion (Co2+, Ni2+, Zn2+). The structures of the polymers are characterized by means of fourier transform infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy, the results show good agreement with the proposed structures. Thermogravimetric analysis measurements exhibit that the metal coordination polymers possess good thermal stability with high thermal decomposition temperature (thermally stable up to 405–510°C). More importantly, the thermal decomposition temperature of Py-N-PBIS-(Co2+, Ni2+, Zn2+) can be nondestructively detected by taking advantage of the fluorescence quenching effect of metal coordination to 2,6-Bis(2-benzimidazolyl)pyridine structure.

Synthesis and properties of fluorinated poly(ester-imide)s

1995 ◽  
Vol 7 (4) ◽  
pp. 411-420 ◽  
Author(s):  
M Bruma ◽  
I Sava ◽  
F Mercer ◽  
I Negulescu ◽  
W Daly ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Dielectric Constant ◽  
Glass Transition ◽  
Decomposition Temperature ◽  
High Thermal Stability ◽  
Low Dielectric Constant ◽  
Initial Decomposition Temperature ◽  
Low Dielectric ◽  
Flexible Films ◽  
High Boiling Point

A series of new, fluorinated poly(ester-imides)s has been synthesized by solution condensation, in a high-boiling-point solvent, of dihydroxy compounds containing imide and hexafluoroisopropylidene units with diacid chlorides containing preformed ester groups. Solutions of these polymers in NMP or in a mixture of trifluoroacetic acid with chloroform were cast into colourless, thin, flexible films having a low dielectric constant. These polymers show high thermal stability, with the initial decomposition temperature being over 400cC. The glass transition temperature is in the range 215-272C for fully aromatic structures and is about 170 TC for those polymers containing some ethylene groups along with aromatic ones. All these characteristics are discussed and compared with those of related poly(esterimide)s which do not contain 6F groups.

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