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Shiyong Yang - One of the best experts on this subject based on the ideXlab platform.
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preparation of Fluorinated Polyimides with bulky structure and their gas separation performance correlated with microstructure
Polymer, 2015Co-Authors: Hui Tong, Shiyong Yang, Hongxia Guo, Lin FanAbstract:The Fluorinated Polyimides with high fractional free volume were prepared from 6FDA and aromatic diamines with bulky triptycene and pendent phenyl moieties. These polymers showed excellent solubility, high thermal stabilities and outstanding mechanical properties. The correlation of gas separation performance with the microstructure of these polyimide membranes was investigated. The results indicated that the GSPI-P membranes based on the diamines with pendent phenyl moieties exhibited higher fractional free volumes than GSPI-T membranes derived from diamines with triptycene moieties; as a result, the former gave the much higher permeability coefficients. The gas permeability of these membranes is strongly depended on their free volume and also affected by fluorine content. The GSPI-P membranes also provided good selectivity for CO2/CH4 and CO2/N-2 gas pairs because their appropriate cavity size is favorable to separate the CO2 from the other gases. (C) 2015 Elsevier Ltd. All rights reserved.
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preparation of Fluorinated Polyimides with bulky structure and their gas separation performance correlated with microstructure
Polymer, 2015Co-Authors: Hui Tong, Shiyong Yang, Hongxia Guo, Lin FanAbstract:Abstract The Fluorinated Polyimides with high fractional free volume were prepared from 6FDA and aromatic diamines with bulky triptycene and pendent phenyl moieties. These polymers showed excellent solubility, high thermal stabilities and outstanding mechanical properties. The correlation of gas separation performance with the microstructure of these polyimide membranes was investigated. The results indicated that the GSPI-P membranes based on the diamines with pendent phenyl moieties exhibited higher fractional free volumes than GSPI-T membranes derived from diamines with triptycene moieties; as a result, the former gave the much higher permeability coefficients. The gas permeability of these membranes is strongly depended on their free volume and also affected by fluorine content. The GSPI-P membranes also provided good selectivity for CO2/CH4 and CO2/N2 gas pairs because their appropriate cavity size is favorable to separate the CO2 from the other gases.
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synthesis and characterization of highly optical transparent and low dielectric constant Fluorinated Polyimides
Polymer, 2009Co-Authors: Liming Tao, Haixia Yang, Jingang Liu, Lin Fan, Shiyong YangAbstract:Abstract Multitrifluoromethyl-substituted aromatic diamines, 1,1-bis[4-(4′- amino-2′-trifluoromethylphenoxy)phenyl]-1-(3″-trifluoromethylphenyl)-2,2,2-trifluoroethane (12FDA) and 1,1-bis[4-(4′-amino-2′-trifluoromethylphenoxy)phenyl]-1-[3″,5″-bis (trifluoromethyl)phenyl]-2,2,2-trifluoroethane (15FDA) were synthesized, which were employed to react with various aromatic dianhydrides to yield a series of highly Fluorinated Polyimides. The Fluorinated Polyimides synthesized showed great solubility with inherent viscosities of 0.47–0.69 dL/g. The strong and tough polyimide films exhibited good thermal stability with the glass transition temperature (Tg) of 209–239 °C and outstanding mechanical properties with the tensile strengths of 88–111 MPa and tensile modulus of 2.65–3.17 GPa. Dielectric constants of as low as 2.49 and low moisture absorptions (0.17–0.66%) were measured. The Fluorinated polyimide films (7–10 μm in thickness) also showed highly optical transparency with light transmittance at 450 nm of as high as 97.0% and cutoff wavelength of as low as 298 nm. The average refractive indices and birefringence of the Fluorinated polyimide films were measured in the range of 1.5060–1.5622 and 0.0036–0.0095, respectively. PI-7 and PI-8 exhibited low light-absorption in the near-infrared region, especially at the optocommunication wavelength of 1310 nm and 1550 nm.
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synthesis and characterization of novel Fluorinated Polyimides derived from 1 1 bis 4 aminophenyl 1 3 trifluoromethylphenyl 2 2 2 trifluoroethane and aromatic dianhydrides
European Polymer Journal, 2008Co-Authors: Lin Fan, Shiyong YangAbstract:Abstract A novel Fluorinated aromatic diamine 1,1′-bis(4-aminophenyl)-1-(3-trifluoromethylphenyl)-2,2,2-trifluoroethane (6FDAM) was synthesized in a simple procedure, which was then employed to prepare a series of Fluorinated Polyimides with commercial aromatic dianhydrides, such as pyromellitic dianhydride (PMDA), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane (6FDA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4′-oxydiphthalic anhydride (ODPA). The Polyimides exhibited good solubility in strong dipolar solvents such as NMP, DMAc, DMF and m-cresol as well as some of low boiling point organic solvents of THF and CHCl3, etc. Experimental results indicated the Polyimides possessed low moisture adsorptions of 0.42–0.95%, low dielectric constant of 2.71–2.95 at 1 MHz, high dielectric strength of 92.0–122.6 kV/mm and good optical transparency with cutoff wavelengths of UV–vis at 330–375 nm. The Polyimides also exhibited good mechanical properties as well as excellent thermal and thermo-oxidative stability. The Fluorinated Polyimides possessed better solubility, lower dielectric constant and water adsorption as well as higher optical transparency than the representative non-Fluorinated polyimide derived from PMDA and 4,4′-oxydianiline (ODA).
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organo soluble Fluorinated Polyimides derived from bis trifluoromethyl substituted aromatic diamines and various aromatic dianhydrides
High Performance Polymers, 2006Co-Authors: Jingang Liu, Lin Fan, Xiaojuan Zhao, Shiyong YangAbstract:A new diamine monomer with bis-trifluoromethyl-substituted phenyl in the side chain, α,α-bis (4-amino-3,5-dimethylphenyl)-3′,5′-bis(trifluoromethyl)phenyl methane (6FMA) was successfully synthesized. A series of Fluorinated Polyimides (PI-IIa-d) were prepared by reacting the diamine with various aromatic dianhydrides. For comparison, another series of Polyimides (PI-Ia-d) derived from another diamine with single-trifluoromethyl-substituted phenyl in the side chain, α,α-bis(4-amino-3,5-dimethylphenyl)-3′-trifluoromethyl phenyl methane and the same dianhydrides were also synthesized. The polymers were characterized by inherent viscosity, elemental analysis, Fourier transform-infrared, X-ray, ultraviolet-visible analysis, moisture absorption, thermogravimetric analysis, and differential scanning calorimetry measurements. It was shown that PI-II Polyimides exhibited good film formability, enhanced solubility, good thermal stability, superior optical transparency, and acceptable mechanical properties. In addit...
Shenghuei Hsiao - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of novel Fluorinated Polyimides derived from 1 3 bis 4 amino 2 trifluoromethylphenoxy naphthalene and aromatic dianhydrides
European Polymer Journal, 2010Co-Authors: Shenghuei Hsiao, Chenglin Chung, Wenjeng Guo, Wentung ChenAbstract:Abstract A new structurally asymmetric diamine monomer containing flexible ether linkages and bulky trifluoromethyl substituents, namely 1,3-bis(4-amino-2-trifluoromethylphenoxy)naphthalene, was prepared from 1,3-dihydroxynaphthalene and 2-chloro-5-nitrobenzotrifluoride. New series of Fluorinated Polyimides were synthesized from the diamine with six commercially available aromatic tetracarboxylic dianhydrides using a conventional two-stage process with thermal or chemical imidization. The resulting Polyimides were highly soluble in a variety of organic solvents and could afford transparent and tough films via solution casting. These Polyimides exhibited moderately high glass-transition temperatures (by DSC) of 236–268 °C and softening temperatures (by thermomechanical analysis) of 231–250 °C, and they did not show significant decomposition before 500 °C under either nitrogen or air atmosphere. Also, they revealed low moisture absorptions (0.32–0.78%), low dielectric constants (2.81–3.24 at 10 kHz), and high optical transparency (ultraviolet–visible absorption cutoff wavelengths of 377–426 nm).
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novel organosoluble Fluorinated Polyimides derived from 1 6 bis 4 amino 2 trifluoromethylphenoxy naphthalene and aromatic dianhydrides
Polymer, 2008Co-Authors: Chenglin Chung, Shenghuei HsiaoAbstract:Abstract A novel trifluoromethyl-substituted bis(ether amine) monomer, 1,6-bis(4-amino-2-trifluoromethylphenoxy)naphthalene, was prepared through the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 1,6-dihydroxynaphthalene in the presence of potassium carbonate in dimethyl sulfoxide, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new Fluorinated Polyimides were synthesized from the diamine with various commercially available aromatic tetracarboxylic dianhydrides via a conventional two-stage process with the thermal or chemical imidization of the poly(amic acid) precursors. Most of the Polyimides obtained from both routes were soluble in many organic solvents such as N-methyl-2-pyrrolidone and N,N-dimethylacetamide. All the Polyimides could afford transparent, flexible, and strong films with low moisture absorptions of 0.12–0.52% and low dielectric constants of 2.75–3.13 at 10 kHz. Thin films of these Polyimides showed an UV–vis absorption cutoff wavelength at 376–428 nm, and those of Polyimides from 4,4′-oxydiphthalic dianhydride (ODPA) and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) were essentially colorless. The Polyimides exhibited excellent thermal stability, with decomposition temperatures (at 10% weight loss) above 530 °C in both air and nitrogen atmospheres and glass transition temperatures (Tgs) in the range of 241–298 °C. For a comparative study, some properties of the present Fluorinated Polyimides were compared with those of structurally related ones prepared from 1,6-bis(4-aminophenoxy)naphthalene and 2,6-bis(4-amino-2-trifluoromethylphenoxy)naphthalene.
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Organosoluble, Low-Colored Fluorinated Polyimides Based on 1,1-Bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane
Journal of Polymer Research, 2006Co-Authors: Chenglin Chung, Tuan-wen Tzu, Shenghuei HsiaoAbstract:A novel trifluoromethyl-substituted bis(ether amine) monomer, 1,1-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane, was synthesized that led to a series of novel Fluorinated Polyimides via chemical imidization route when reacted with various commercially available aromatic tetracarboxylic dianhydrides. These Polyimides were highly soluble in a variety of organic solvents such as N -methyl-2-pyrrolidone and N , N - dimethylacetamide, and most of them could afford transparent, low-colored, and tough films. These Polyimides exhibited glass-transition temperatures ( T _gs) of 227–269 °C and showed no significant decomposition below 500 °C under either nitrogen or air atmosphere. These Polyimides had low dielectric constants of 2.87–3.17 at 10 kHz, low water uptake of 0.13%–0.58%, and an ultraviolet-visible absorption cutoff wavelength at 364–410 nm. For a comparative study, a series of analogous Polyimides based on 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane were also prepared and characterized.
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novel organosoluble light colored Fluorinated Polyimides based on 2 2 bis 4 amino 2 trifluoromethylphenoxy biphenyl or 2 2 bis 4 amino 2 trifluoromethylphenoxy 1 1 binaphthyl
Journal of Polymer Science Part A, 2004Co-Authors: Chin-ping Yang, Shenghuei Hsiao, Cheyu Tsai, Gueysheng LiouAbstract:Two series of Fluorinated Polyimides were prepared from 2,2-bis(4-amino- 2-trifluoromethylphenoxy)biphenyl (2) and 2,2-bis(4-amino-2-trifluoromethylphe- noxy)-1,1-binaphthyl (4) with various aromatic dianhydrides via a conventional, two- step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by chemical or thermal cyclodehydration. The inherent viscosities of the Polyimides ranged from 0.54 to 0.73 and 0.19 to 0.36 dL/g, respectively. All the fluori- nated Polyimides were soluble in many polar organic solvents, such as N,N-dimethyl- acetamide and N-methylpyrrolidone, and afforded transparent and light-colored films via solution-casting. These Polyimides showed glass-transition temperatures in the ranges of 222-280 and 257-351 °C by DSC, softening temperatures in the range of 264 -301 °C by thermomechanical analysis, and a decomposition temperature for 10% weight loss above 520 °C both in nitrogen and air atmospheres. The Polyimides had low moisture absorptions of 0.23- 0.58%, low dielectric constants of 2.84 -3.61 at 10 kHz, and an ultraviolet-visible absorption cutoff wavelength at 351- 434 nm. CoPolyimides derived from the same dianhydrides with an equimolar mixture of 4,4-oxydianiline and diamine 2 or 4 were also prepared and characterized. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2416 -2431, 2004
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synthesis and characterization of novel Fluorinated Polyimides based on 2 7 bis 4 amino 2 trifluoromethylphenoxy naphthalene
Journal of Polymer Science Part A, 2003Co-Authors: Shenghuei Hsiao, Chin-ping Yang, Chenglin ChungAbstract:A new trifluoromethyl-substituted bis(ether amine) monomer, 2,7-bis(4-amino-2-trifluoromethylphenoxy)naphthalene, was synthesized. It led to a series of novel Fluorinated Polyimides by thermal and chemical imidization routes when reacted with various commercially available aromatic tetracarboxylic dianhydrides. Most of the Polyimides obtained from both routes were soluble in many organic solvents, such as N,N-dimethylacetamide. All the Polyimides could afford transparent, flexible, and strong films with low moisture absorptions of 0.3-0.6%, low dielectric constants of 2.52-3.27 at 10 kHz, and an ultraviolet-visible absorption cutoff wavelength at 377-436 nm. The glass-transition temperatures of the Polyimides were in the range of 244-297 °C, and the 5% weight-loss temperatures were higher than 550 °C. For a comparative study, a series of analogous Polyimides based on 2,7-bis(4-aminophenoxy)naphthalene were also prepared and characterized.
Feng-ling Qing - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of novel Fluorinated Polyimides derived from bis 4 4 aminophenoxy phenyl 3 5 bis trifluoromethyl phenyl phosphine oxide
Polymer, 2007Co-Authors: Yuanqin Zhu, Pinqiao Zhao, Xuediao Cai, Wei-dong Meng, Feng-ling QingAbstract:Abstract A novel Fluorinated aromatic diamine, bis[4-(4′-aminophenoxy)phenyl]-3,5-bis(trifluoromethyl)phenyl phosphine oxide, was synthesized. A series of new Fluorinated Polyimides containing phosphine oxide was prepared from the novel diamine with various commercially available aromatic dianhydrides. All the Fluorinated Polyimides show high glass transition temperatures, excellent thermal stability, and good solubility in common organic solvents.
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Synthesis and characterization of novel Fluorinated Polyimides derived from bis[4-(4′-aminophenoxy)phenyl]-3,5-bis(trifluoromethyl)phenyl phosphine oxide
Polymer, 2007Co-Authors: Yuanqin Zhu, Pinqiao Zhao, Xuediao Cai, Wei-dong Meng, Feng-ling QingAbstract:Abstract A novel Fluorinated aromatic diamine, bis[4-(4′-aminophenoxy)phenyl]-3,5-bis(trifluoromethyl)phenyl phosphine oxide, was synthesized. A series of new Fluorinated Polyimides containing phosphine oxide was prepared from the novel diamine with various commercially available aromatic dianhydrides. All the Fluorinated Polyimides show high glass transition temperatures, excellent thermal stability, and good solubility in common organic solvents.
Chin-ping Yang - One of the best experts on this subject based on the ideXlab platform.
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light colored Fluorinated Polyimides based on 2 5 bis 4 amino 2 trifluoromethylphenoxy biphenyl and various aromatic dianhydrides
Journal of Applied Polymer Science, 2006Co-Authors: Chin-ping Yang, Yungchung ChenAbstract:A novel trifluoromethyl-containing aromatic diamine monomer, 2,5-bis (4-amino-2-trifluoromethylphenoxy)biphenyl (2), was prepared through the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and phenylhydroquinone in the presence of potassium carbonate to yield the intermediate dinitro compound (1), followed by catalytic reduction with hydrazine and Pd/C. A series of Fluorinated Polyimides (code 5a–f) were synthesized from diamine (2) with six commercially available aromatic dianhydrides using a standard two-stage process with thermal or chemical imidization of poly(amic acid). Most of Fluorinated Polyimides showed good solubility at a concentration of 5–10 wt % and even in pyridine and dioxane. For improving solubility of 5c, coPolyimides (5c/a–f) were also prepared from 2 and a pair of dianhydrides (3c/a–f), which were mixed in the molar ratio 1:1. All the polyimide films had a tensile strength in the range from 73 to 112 MPa, an elongation at break within a range of 9–23%, and an initial modulus in the range of 1.6–2.2 GPa. These Polyimides exhibited glass transition temperatures of 220–267°C and showed no significant decomposition below 500°C under either nitrogen or air atmosphere. In comparison with the analogous nonFluorinated Polyimides based on 2,5-bis (4-aminophenoxy) biphenyl (2′), the Fluorinated Polyimides showed better solubility as well as reduced color intensity, lower dielectric constant, and moisture absorption. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4101–4110, 2006
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Organosoluble and Light-colored Fluorinated Polyimides from 2,2-Bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]sulfone and Aromatic Dianhydrides
Journal of Polymer Research, 2005Co-Authors: Chin-ping YangAbstract:A new trifluoromethyl-substituted diamine monomer, 2,2-bis[4-(4-amino-2-trifluoromethylpenoxy)phenyl]sulfone ( II ), was prepared through the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 4,4’-sulfonyl diphenol in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Novel Fluorinated Polyimides V _a–f having inherent viscosities ranging from 0.74 to 1.14 dL/g were synthesized from the diamine II with various aromatic dianhydrides via thermal imidization of poly(amic acid). Most of V series were soluble in the all test solvents, except V _b(H). These polyimide films had strengths at yield of 94–119 MPa, tensile strengths of 90–118 MPa, elongations to break of 10–16%, and initial moduli of 2.0–2.4 GPa. The glass transition temperature ( T _g) of these polymers were in the range of 244–297 ^○C, their 10% weight loss temperatures were above 520 ^○C under ether nitrogen or air atmosphere, and left more than 45 wt% residue even at 800 ^○C in nitrogen. Compared with Polyimides VII based on 4,4’-bis(3-aminophenoxy)diphenyl sulfone ( II ’), V showed better solubility and lower color intensity, dielectric constant, and moisture absorption. Their films had cutoff wavelengths between 355–402 nm, b ^* values ranging from 6.8 to 32.9, dielectric constants of 3.32–4.27 (1 MHz), and moisture absorptions in the range of 0.27–0.62 wt%.
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novel organosoluble light colored Fluorinated Polyimides based on 2 2 bis 4 amino 2 trifluoromethylphenoxy biphenyl or 2 2 bis 4 amino 2 trifluoromethylphenoxy 1 1 binaphthyl
Journal of Polymer Science Part A, 2004Co-Authors: Chin-ping Yang, Shenghuei Hsiao, Cheyu Tsai, Gueysheng LiouAbstract:Two series of Fluorinated Polyimides were prepared from 2,2-bis(4-amino- 2-trifluoromethylphenoxy)biphenyl (2) and 2,2-bis(4-amino-2-trifluoromethylphe- noxy)-1,1-binaphthyl (4) with various aromatic dianhydrides via a conventional, two- step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by chemical or thermal cyclodehydration. The inherent viscosities of the Polyimides ranged from 0.54 to 0.73 and 0.19 to 0.36 dL/g, respectively. All the fluori- nated Polyimides were soluble in many polar organic solvents, such as N,N-dimethyl- acetamide and N-methylpyrrolidone, and afforded transparent and light-colored films via solution-casting. These Polyimides showed glass-transition temperatures in the ranges of 222-280 and 257-351 °C by DSC, softening temperatures in the range of 264 -301 °C by thermomechanical analysis, and a decomposition temperature for 10% weight loss above 520 °C both in nitrogen and air atmospheres. The Polyimides had low moisture absorptions of 0.23- 0.58%, low dielectric constants of 2.84 -3.61 at 10 kHz, and an ultraviolet-visible absorption cutoff wavelength at 351- 434 nm. CoPolyimides derived from the same dianhydrides with an equimolar mixture of 4,4-oxydianiline and diamine 2 or 4 were also prepared and characterized. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2416 -2431, 2004
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synthesis and properties of Fluorinated Polyimides based on 1 4 bis 4 amino 2 trifluoromethylphenoxy 2 5 di tert butylbenzene and various aromatic dianhydrides
Journal of Polymer Science Part A, 2004Co-Authors: Chin-ping Yang, Fengzhi HsiaoAbstract:A novel Fluorinated diamine monomer, 1,4-bis(4-amino-2-trifluoromethylphenoxy)-2,5-di-tert-butylbenzene (2), was prepared through the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 2,5-di-tert-butylhydroquinone in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Fluorinated Polyimides (5a-5f) were synthesized from diamine 2 and various aromatic dianhydrides (3a-3f) via thermal or chemical imidization. These polymers had inherent viscosities of 0.77-1.01 dL/g. The 5 series Polyimides were soluble in N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide and were even soluble in dioxane, tetrahydrofuran, and dichloromethane. 5(C) showed cutoff wavelengths between 363 and 404 nm and yellowness index (b*) values of 6.5-40.2. The polyimide films had tensile strengths of 93-114 MPa, elongations to break of 9-12%, and initial moduli of 1.7-2.1 GPa. The glass-transition temperatures were 255-288 °C. The temperatures of 10% weight loss were all above 460 °C in air or nitrogen atmospheres. In comparison with a nonFluorinated polyimide series based on 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene, the 5 series showed better solubility and lower color intensity, dielectric constants, and moisture absorption.
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synthesis and characterization of novel Fluorinated Polyimides based on 2 7 bis 4 amino 2 trifluoromethylphenoxy naphthalene
Journal of Polymer Science Part A, 2003Co-Authors: Shenghuei Hsiao, Chin-ping Yang, Chenglin ChungAbstract:A new trifluoromethyl-substituted bis(ether amine) monomer, 2,7-bis(4-amino-2-trifluoromethylphenoxy)naphthalene, was synthesized. It led to a series of novel Fluorinated Polyimides by thermal and chemical imidization routes when reacted with various commercially available aromatic tetracarboxylic dianhydrides. Most of the Polyimides obtained from both routes were soluble in many organic solvents, such as N,N-dimethylacetamide. All the Polyimides could afford transparent, flexible, and strong films with low moisture absorptions of 0.3-0.6%, low dielectric constants of 2.52-3.27 at 10 kHz, and an ultraviolet-visible absorption cutoff wavelength at 377-436 nm. The glass-transition temperatures of the Polyimides were in the range of 244-297 °C, and the 5% weight-loss temperatures were higher than 550 °C. For a comparative study, a series of analogous Polyimides based on 2,7-bis(4-aminophenoxy)naphthalene were also prepared and characterized.
Lin Fan - One of the best experts on this subject based on the ideXlab platform.
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preparation of Fluorinated Polyimides with bulky structure and their gas separation performance correlated with microstructure
Polymer, 2015Co-Authors: Hui Tong, Shiyong Yang, Hongxia Guo, Lin FanAbstract:Abstract The Fluorinated Polyimides with high fractional free volume were prepared from 6FDA and aromatic diamines with bulky triptycene and pendent phenyl moieties. These polymers showed excellent solubility, high thermal stabilities and outstanding mechanical properties. The correlation of gas separation performance with the microstructure of these polyimide membranes was investigated. The results indicated that the GSPI-P membranes based on the diamines with pendent phenyl moieties exhibited higher fractional free volumes than GSPI-T membranes derived from diamines with triptycene moieties; as a result, the former gave the much higher permeability coefficients. The gas permeability of these membranes is strongly depended on their free volume and also affected by fluorine content. The GSPI-P membranes also provided good selectivity for CO2/CH4 and CO2/N2 gas pairs because their appropriate cavity size is favorable to separate the CO2 from the other gases.
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preparation of Fluorinated Polyimides with bulky structure and their gas separation performance correlated with microstructure
Polymer, 2015Co-Authors: Hui Tong, Shiyong Yang, Hongxia Guo, Lin FanAbstract:The Fluorinated Polyimides with high fractional free volume were prepared from 6FDA and aromatic diamines with bulky triptycene and pendent phenyl moieties. These polymers showed excellent solubility, high thermal stabilities and outstanding mechanical properties. The correlation of gas separation performance with the microstructure of these polyimide membranes was investigated. The results indicated that the GSPI-P membranes based on the diamines with pendent phenyl moieties exhibited higher fractional free volumes than GSPI-T membranes derived from diamines with triptycene moieties; as a result, the former gave the much higher permeability coefficients. The gas permeability of these membranes is strongly depended on their free volume and also affected by fluorine content. The GSPI-P membranes also provided good selectivity for CO2/CH4 and CO2/N-2 gas pairs because their appropriate cavity size is favorable to separate the CO2 from the other gases. (C) 2015 Elsevier Ltd. All rights reserved.
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synthesis and characterization of highly optical transparent and low dielectric constant Fluorinated Polyimides
Polymer, 2009Co-Authors: Liming Tao, Haixia Yang, Jingang Liu, Lin Fan, Shiyong YangAbstract:Abstract Multitrifluoromethyl-substituted aromatic diamines, 1,1-bis[4-(4′- amino-2′-trifluoromethylphenoxy)phenyl]-1-(3″-trifluoromethylphenyl)-2,2,2-trifluoroethane (12FDA) and 1,1-bis[4-(4′-amino-2′-trifluoromethylphenoxy)phenyl]-1-[3″,5″-bis (trifluoromethyl)phenyl]-2,2,2-trifluoroethane (15FDA) were synthesized, which were employed to react with various aromatic dianhydrides to yield a series of highly Fluorinated Polyimides. The Fluorinated Polyimides synthesized showed great solubility with inherent viscosities of 0.47–0.69 dL/g. The strong and tough polyimide films exhibited good thermal stability with the glass transition temperature (Tg) of 209–239 °C and outstanding mechanical properties with the tensile strengths of 88–111 MPa and tensile modulus of 2.65–3.17 GPa. Dielectric constants of as low as 2.49 and low moisture absorptions (0.17–0.66%) were measured. The Fluorinated polyimide films (7–10 μm in thickness) also showed highly optical transparency with light transmittance at 450 nm of as high as 97.0% and cutoff wavelength of as low as 298 nm. The average refractive indices and birefringence of the Fluorinated polyimide films were measured in the range of 1.5060–1.5622 and 0.0036–0.0095, respectively. PI-7 and PI-8 exhibited low light-absorption in the near-infrared region, especially at the optocommunication wavelength of 1310 nm and 1550 nm.
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synthesis and characterization of novel Fluorinated Polyimides derived from 1 1 bis 4 aminophenyl 1 3 trifluoromethylphenyl 2 2 2 trifluoroethane and aromatic dianhydrides
European Polymer Journal, 2008Co-Authors: Lin Fan, Shiyong YangAbstract:Abstract A novel Fluorinated aromatic diamine 1,1′-bis(4-aminophenyl)-1-(3-trifluoromethylphenyl)-2,2,2-trifluoroethane (6FDAM) was synthesized in a simple procedure, which was then employed to prepare a series of Fluorinated Polyimides with commercial aromatic dianhydrides, such as pyromellitic dianhydride (PMDA), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane (6FDA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4′-oxydiphthalic anhydride (ODPA). The Polyimides exhibited good solubility in strong dipolar solvents such as NMP, DMAc, DMF and m-cresol as well as some of low boiling point organic solvents of THF and CHCl3, etc. Experimental results indicated the Polyimides possessed low moisture adsorptions of 0.42–0.95%, low dielectric constant of 2.71–2.95 at 1 MHz, high dielectric strength of 92.0–122.6 kV/mm and good optical transparency with cutoff wavelengths of UV–vis at 330–375 nm. The Polyimides also exhibited good mechanical properties as well as excellent thermal and thermo-oxidative stability. The Fluorinated Polyimides possessed better solubility, lower dielectric constant and water adsorption as well as higher optical transparency than the representative non-Fluorinated polyimide derived from PMDA and 4,4′-oxydianiline (ODA).
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organo soluble Fluorinated Polyimides derived from bis trifluoromethyl substituted aromatic diamines and various aromatic dianhydrides
High Performance Polymers, 2006Co-Authors: Jingang Liu, Lin Fan, Xiaojuan Zhao, Shiyong YangAbstract:A new diamine monomer with bis-trifluoromethyl-substituted phenyl in the side chain, α,α-bis (4-amino-3,5-dimethylphenyl)-3′,5′-bis(trifluoromethyl)phenyl methane (6FMA) was successfully synthesized. A series of Fluorinated Polyimides (PI-IIa-d) were prepared by reacting the diamine with various aromatic dianhydrides. For comparison, another series of Polyimides (PI-Ia-d) derived from another diamine with single-trifluoromethyl-substituted phenyl in the side chain, α,α-bis(4-amino-3,5-dimethylphenyl)-3′-trifluoromethyl phenyl methane and the same dianhydrides were also synthesized. The polymers were characterized by inherent viscosity, elemental analysis, Fourier transform-infrared, X-ray, ultraviolet-visible analysis, moisture absorption, thermogravimetric analysis, and differential scanning calorimetry measurements. It was shown that PI-II Polyimides exhibited good film formability, enhanced solubility, good thermal stability, superior optical transparency, and acceptable mechanical properties. In addit...