Aromatic Poly(ether imide oxadiazole)s

1992 ◽  
Vol 4 (2) ◽  
pp. 73-80 ◽  
Author(s):  
F. W. Mercer
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Aprotic Solvent ◽  
Dielectric Constants ◽  
Aromatic Diamines ◽  
Glass Transition Temperatures ◽  
Good Thermal Stability ◽  
Polar Aprotic Solvent ◽  
Carbonate Reaction ◽  
Poly Imide

Two oxadiazole containing aromatic diamines were synthesized. The diamines were prepared by reaction of aminophenols with 2,5-bis(4-fluorophenyl)-4l3,4-oxadiazole in a polar aprotic solvent in the presence of potassium carbonate. Reaction of the resulting 2,5-bis(4-(aminophenoxy)phenyl)-1,3,4-oxadiazoles with dianhydrides gave a series of polymeric amic acids. Thermal treatment yielded poly(imide ether oxadazole) films which displayed good thermal stability, flexibility, and glass transition temperatures ranging from 241 to 344C. The dielectric constants of the films were characterized as a function of relative humidity.

Organosoluble and transparent cardo polyimides with high Tg derived from 9,9-bis(4-aminophenyl)xanthene

2018 ◽  
Vol 31 (8) ◽  
pp. 909-918 ◽  
Author(s):  
Xiao-Lan Zhang ◽  
Cheng Song ◽  
Mei-Hong Wei ◽  
Zhen-Zhong Huang ◽  
Shou-Ri Sheng
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Glass Transition ◽  
Amic Acid ◽  
Dielectric Constants ◽  
Cutoff Wavelength ◽  
One Pot ◽  
Glass Transition Temperatures ◽  
Good Thermal Stability ◽  
Step Procedure

9,9-Bis(4-aminophenyl)xanthene (BAPX) was prepared simply and effectively via one-pot, two-step procedure using xanthenone and aniline as main substrates. The monomer BAPX was reacted with six aromatic dianhydrides in N, N-dimethylacetamide (DMAc) to yield the corresponding polyimides (PIs) via the poly(amic acid) precursors and subsequent thermal or chemical imidization. The resulting PIs exhibited good thermal stability with glass transition temperatures of 308–348°C, initial decomposition temperatures of 470–510°C, 10% weight loss temperatures of 540–565°C, and char yields of 55–59% at 800°C in nitrogen, respectively. All polymers were amorphous and readily soluble in organic solvents such as N-methyl-2-pyrrolidone and DMAc. The PI films had tensile strengths of 71–92 MPa, tensile moduli of 1.91–2.35 GPa, and elongations at break of 5–13%. Meanwhile, these polymer films also had high optical transparency with a cutoff wavelength in the range of 367–415 nm, lower dielectric constants (3.02–3.34 at 10 MHz), and low water uptake of 0.30–0.52%.

Synthesis and characterization of aromatic poly(ether ketone amide)s

1993 ◽  
Vol 5 (3) ◽  
pp. 187-196 ◽  
Author(s):  
Frank W Mercer
Keyword(s):  
Thermal Stability ◽  
Benzoyl Chloride ◽  
Aprotic Solvent ◽  
Dielectric Constants ◽  
Synthesis And Characterization ◽  
Good Thermal Stability ◽  
Ether Ketone ◽  
T Values ◽  
General Method

A general method for the preparation of amide-containing aromatic polyether ketones has been developed. Polymerization is based on a ketone-activated halo displacement in amide-containing bis(4-fluorobenzoyl) moieties by phenoxides. N,N-Bis[4-(4-fluorobenzoyl)-(4-phenoxyphenylJ]terephthalamide and 4-[(4-fiuorobenzoyl)-(4-phenoxyphenylcarbamoyl)]-N-[(4-fluorobenzoyl)-(4-phenoxyphenyl)]phthalimide were prepared by reaction of 4-fluoro-benzoyl chloride with N,N.bis(4-phenoxyphenyl)terephthalamide and 4-(4.phenoxy-phenylcarbamoyl)-N-(4-phenoxyphenyl)phthalimide, respectively, in dichloromethane in the presence of aluminum chloride. Reaction of N,N-bis[4-(4-fluorobenzoyl)-(4-phenoxyphenyl)]-terephthalamide and 4-[(4-fluorobenzoyl(4-phenoxyphenylcarbamoyl)]-N-[(4-fluorobenzoyl)-(4-phenoxyphenyl)]phthalimide with diphenols in an aprotic solvent in the presence of potassium carbonate gave a series of aromatic poly(ether ketone amide)s. Films of the aromatic poly(ether ketone amide)s displayed good thermal stability, flexibility, and T, values ranging from 134 to 186 CC. The dielectric constants of the films were characterized as a function of relative humidity (RH).

Synthesis, characterization and thermal crosslinking behavior of new poly(aryl ether sulfone)s based on naphthalene isomers

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Zhang Ying ◽  
Zhang Yunhe ◽  
Niu Yaming ◽  
Na Ying ◽  
Jiang Zhenhua
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Glass Transition ◽  
Free Radicals ◽  
Crosslinking Reaction ◽  
Transition Temperatures ◽  
Aryl Ether ◽  
Glass Transition Temperatures ◽  
Good Thermal Stability ◽  
Thermal Crosslinking

AbstractFour new poly(aryl ether sulfone)s containing naphthalene rings were synthesized from 1,5- and 2,7-bis-(4-fluorosulfonyl)naphthalene isomers with different diphenols. These polymers exhibited high glass transition temperatures and good thermal stability. The glass transition temperatures ranged from 220 to 236°C and the 5% weight-loss temperatures were above 423°C. As the four polymers were treated at 300°C, the glass transition temperatures of polymer series a obviously increased and the polymers became insoluble in common organic solvents including NMP, DMAc, and chloroform, etc., but the series b did not, which indicate that a thermal crosslinking reaction via free radicals happened leading to crosslinked polymers

scholarly journals Preparation and Characterization of Electrospun Fluoro-Containing Poly(imide-benzoxazole) Nano-Fibrous Membranes with Low Dielectric Constants and High Thermal Stability

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 537
Author(s):  
Meng-Ge Huangfu ◽  
Deng-Xiong Shen ◽  
Xin-Xin Zhi ◽  
Yan Zhang ◽  
Yan-Jiang Jia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Dielectric Properties ◽  
High Frequency ◽  
Rapid Development ◽  
Dielectric Constants ◽  
Polymer Materials ◽  
Aromatic Diamines ◽  
Low Dielectric ◽  
Fibrous Membranes ◽  
Poly Imide

The rapid development of advanced high-frequency mobile communication techniques has advanced urgent requirements for polymer materials with high-temperature resistance and good dielectric properties, including low dielectric constants (low-Dk) and low dielectric dissipation factors (low-Df). The relatively poor dielectric properties of common polymer candidates, such as standard polyimides (PIs) greatly limited their application in high-frequency areas. In the current work, benzoxazole units were successfully incorporated into the molecular structures of the fluoro-containing PIs to afford the poly(imide-benzoxazole) (PIBO) nano-fibrous membranes (NFMs) via electrospinning fabrication. First, the PI NFMs were prepared by the electrospinning procedure from organo-soluble PI resins derived from 2,2′-bis(3,4-dicarboxy-phenyl)hexafluoropropane dianhydride (6FDA) and aromatic diamines containing ortho-hydroxy-substituted benzamide units, including 2,2-bis[3-(4-aminobenzamide)-4-hydroxylphenyl]hexafluoropropane (p6FAHP) and 2,2-bis[3-(3-aminobenzamide)-4-hydroxyphenyl]hexafluoropropane (m6FAHP). Then, the PI NFMs were thermally dehydrated at 350 °C in nitrogen to afford the PIBO NFMs. The average fiber diameters (dav) for the PIBO NFMs were 1225 nm for PIBO-1 derived from PI-1 (6FDA-p6FAHP) precursor and 816 nm for PIBO-2 derived from PI-2 (6FDA-m6FAHP). The derived PIBO NFMs showed good thermal stability with the glass transition temperatures (Tgs) over 310 °C and the 5% weight loss temperatures (T5%) higher than 500 °C in nitrogen. The PIBO NFMs showed low dielectric features with the Dk value of 1.64 for PIBO-1 and 1.82 for PIBO-2 at the frequency of 1 MHz, respectively. The Df values were in the range of 0.010~0.018 for the PIBO NFMs.

Synthesis and characterization of aromatic poly(ether ketone oxadiazole)s

1993 ◽  
Vol 5 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Frank W Mercer
Keyword(s):  
Thermal Stability ◽  
Relative Humidity ◽  
Aprotic Solvent ◽  
Dielectric Constants ◽  
Aluminium Chloride ◽  
Synthesis And Characterization ◽  
Good Thermal Stability ◽  
Ether Ketone ◽  
General Method

A general method for the preparation of oxadiazole containing aromatic poly(ether ketone)s has been developed. Polymerization is based on a ketone-activated halo displacement in oxadiazole containing bis(4-fluorobenzoyl) moieties by phenoxides. 2,5-bis[4-(4-fluorobenzoyl-(4-phenoxyphenyl)]-1,3,4-oxadiazole was prepared by reaction of 4-fluorobenzoyl chloride with 2,5-bis(4-phenoxyphenyl)-1,3,4-oxadiazole in dichloromethane in the presence of aluminium chloride. Reaction of 2,5-bis[4-(4-fiuorobenzoyl)-(4-phenoxyphenyl)]-1,3,4-oxadiazole with diphenols in an aprotic solvent in the presence of potassium carbonate gave a series of aromatic poly(ether ketone oxadiazole)s. Films of the aromatic poly(ether ketone oxadiazole)s displayed good thermal stability, flexibility, and Ts s ranging from 172 to 218 C. The dielectric constants of the films were characterized as a function of relative humidity (RH).

Synthesis and Properties of Aromatic Poly(Ether Ketone Pyridazine)s

1993 ◽  
Vol 5 (4) ◽  
pp. 275-283 ◽  
Author(s):  
Frank W Mercer
Keyword(s):  
Thermal Stability ◽  
Relative Humidity ◽  
Potassium Carbonate ◽  
Aluminum Chloride ◽  
Aprotic Solvent ◽  
Dielectric Constants ◽  
Good Thermal Stability ◽  
Ether Ketone ◽  
T Values ◽  
General Method

A general method for the preparation of pyridazine-containing aromatic poly(ether ketone)s has been developed. Polymerization is based on a ketone-activated nucleophilic halo displacement in pyridazine containing bis(4-fluorobenzoyl) moieties by phenoxides. 3,6-Bis(4-fluorobenzoyl-4'-phenoxy-4"-phenoxy)pyridazine was prepared by reaction of 4-fluorobenzoyl chloride with 3,6-bis(4-phenoxyphenoxy)pyrfdazine in dichloromethane in the presence of aluminum chloride. Reaction 3,6-bis(4-fluorobenzoyl-(4-phenoxy-4phenoxy)pyridazine with diphenols in an aprotic solvent in the presence of potassium carbonate gave a series of aromatic poly(ether ketone pyridazine)s. Films of the aromatic poly(ether ketone pyrdazine)s displayed good thermal stability, flexibility, and T. values ranging from 159 to 198 'C. The dielectric constants of the films were characterized as a function of relative humidity (RH).

Study of the crosslinking process in fluorinated poly(imide-amide)s containing pendant cyano groups

1994 ◽  
Vol 6 (3) ◽  
pp. 183-191 ◽  
Author(s):  
M Bruma ◽  
F Mercer ◽  
B Schulz ◽  
R Dietel ◽  
J Fitch ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Dielectric Constant ◽  
Glass Transition ◽  
Transition Temperature ◽  
Aromatic Diamines ◽  
Crosslinking Process ◽  
Thermal Crosslinking ◽  
Cyano Groups ◽  
Poly Imide ◽  
Solution Polycondensation

Fluorinated poly(imide-amide)s containing pendant cyano groups have been synthesized by solution polycondensation of aromatic diamines which contain cyano groups with diacid chlorides which have both hexafluoroisopropylidene and imnide groups. Thermal crosslinking of these polymers has been attempted in NMP, or by heating the polymer films up to 370-400 'C. The solubility, thermal stability, glass transition temperature and dielectric constant of both linear and crosslinked polymers have been studied.

The effect of methyl and methoxy substituents on dianilines for a thermosetting polyimide system

2020 ◽  
Vol 32 (7) ◽  
pp. 801-822 ◽  
Author(s):  
John J La Scala ◽  
Greg Yandek ◽  
Jason Lamb ◽  
Craig M Paquette ◽  
William S Eck ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Glass Transition ◽  
Elevated Temperature ◽  
Methyl Substituent ◽  
Glass Transition Temperatures ◽  
High Performing ◽  
Methoxy Substituent ◽  
Acidic Conditions ◽  
Thermal Stability Of

4,4′-Methylenedianiline (MDA) is widely used in high-temperature polyimide resins, including polymerization of monomer reactants-15. The toxicity of MDA significantly limits the manufacturability using this resin. Modifying the substitution and electronics of MDA could allow for the reduction of toxicity while maintaining the high-performing properties of the materials derived from the modified MDA. The addition of a single methyl substituent, methoxy substituent, location of these substituents, and location of the amine relative to the phenolic bridge were modified as were other non-aniline diamines. Various anilines were condensed with paraformaldehyde under acidic conditions to yield dianilines. These dianilines and diamines were reacted with nadic anhydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in methanol to form the polyamic acid oligomers and heated at elevated temperature to form polyimide oligomers. It was found that the molecular weight of the oligomers derived from MDA alternatives was generally lower than that of MDA oligomers resulting in lower glass transition temperatures ( T gs) and degradation temperatures. Additionally, methoxy substituents further reduce the T g of the polymers versus methyl substituents and reduce the thermal stability of the resin. Methyl-substituted alternatives produced polyimides with similar T gs and degradation temperatures. The toxicity of the MDA alternatives was examined. Although a few were identified with reduced toxicities, the alternatives with properties similar to that of MDA also had high toxicities.

New fluorinated aromatic polyamides based on N,N-bis(4-carboxyphenyl)-4-trifluoromethylaniline

2018 ◽  
Vol 31 (6) ◽  
pp. 613-622 ◽  
Author(s):  
Yu-Ting Zhou ◽  
Zhen-Zhong Huang ◽  
Cheng Song ◽  
Chuan-Chao Tang ◽  
Xiao-Ling Liu ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Silver Chloride ◽  
Dielectric Constants ◽  
Acetonitrile Solution ◽  
Cyclic Voltammograms ◽  
Cutoff Wavelength ◽  
Aromatic Diamines ◽  
Visible Absorption ◽  
Good Thermal Stability ◽  
Silver Silver

A new aromatic diacid monomer, N, N-bis(4-carboxyphenyl)-4-trifluoromethylaniline, was synthesized by the substitution reaction of 4-trifluoromethylaniline with 4-fluorobenzonitrile, followed by alkaline hydrolysis of the dinitrile intermediate. Several polyamides with 4-trifluoromethyltriphenylamine moieties were prepared from the diacid and various aromatic diamines via the direct phosphorylation polycondensation. All the polyamides were amorphous and readily soluble in many polar organic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone, and could be solution-cast into transparent, tough, and flexible films with good mechanical properties. They exhibited good thermal stability with glass transition temperatures of 260–330°C, 10% weight-loss temperatures above 500°C, and char yields higher than 60% at 800°C in nitrogen. These polymers had low dielectric constants of 3.35–3.72 (100 Hz), low water uptake of 1.80–2.60%, and high transparency with an ultraviolet–visible absorption cutoff wavelength in the range of 378–390 nm. Cyclic voltammograms of the polyamide films cast onto an indium-tin oxide–coated glass substrate exhibited a reversible oxidation redox coupled with oxidation half-wave potentials ( E 1/2) of 0.95–1.04 V versus silver/silver chloride in an acetonitrile solution.

Organo-Soluble, Segmented Rigid-Rod Polyimides: Synthesis and Properties

1991 ◽  
Vol 227 ◽  
Author(s):  
F. W. Harris ◽  
S. L. C. Hsu ◽  
C. J. Lee ◽  
B. S. Lee ◽  
F. Arnold ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Glass Transition ◽  
Oxidative Stability ◽  
Organic Solvents ◽  
Dielectric Constants ◽  
Glass Transition Temperatures ◽  
Thermal Expansion Coefficients ◽  
Rigid Rod ◽  
Expansion Coefficients

ABSTRACTSeveral segmented, rigid-rod polyimides have been prepared that are soluble in organic solvents in their fully imidized form. The polymers were prepared from commercial dianhydrides and 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB). Their intrinsic viscosities ranged from 1.0 to 4.9 dL/g. Tough, colorless films could be cast from m-cresol solutions at 100°C. The polymers had glass transition temperatures (Tgs) above 275°C and displayed outstanding thermal and thermo-oxidative stability. Fibers were prepared from the 3,3′,4,4′-tetracarboxybiphenyl dianhydride (BPDA) based polymers that had moduli of 130 GPa and tensile strengths of 3.2 GPa. The thermal expansion coefficients and dielectric constants of thin films (20–25 μm) of the polymers were as low as −2.40×10−6 and 2.5, respectively.

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