Optically transparent and organosoluble poly(ether imide)s based on a bis(ether anhydride) with bulky 3,3′,5,5′-tetramethylbiphenyl moiety and various fluorinated bis(ether amine)s

2016 ◽  
Vol 30 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Yung-Chung Chen ◽  
Sheng-Huei Hsiao

Novel optically transparent and organosoluble poly(ether imide)s (PEIs) were prepared from 4,4′-bis(3,4-dicarboxyphenoxy)-3,3′,5,5′-tetramethylbiphenyl dianhydride and various fluorinated bis(ether amine)s via chemical or thermal imidization. The effects of fluorinated groups and the imidization method on the properties of PEIs were investigated. Fluorinated PEIs prepared by the chemical imidization method exhibited essentially colorless characteristic with cutoff wavelengths lower than 380 nm, and yellowness index (b* values) ranging from 5.2 to 7.3, which are close to that of transparent polyarylate polymer (b* = 3.3). In addition, all fluorinated PEIs showed excellent solubility in common organic solvents. The thermal decomposition temperature at 10% weight loss is higher than 490°C, and the glass transition temperatures are in the range of 245–315°C. The fluorinated PEI series also exhibited low dielectric constants of 2.95–3.29 (1 MHz) and low moisture absorption in the range of 0.17–0.86 wt%, which are lower than the analogous nonfluorinated series.

2012 ◽  
Vol 24 (8) ◽  
pp. 683-691 ◽  
Author(s):  
Cheng-Yuan Shang ◽  
Xiao-Juan Zhao ◽  
Xin Yang ◽  
Ying Zhang ◽  
Wei Huang

A novel epoxy resin containing trifluoromethyl and pendant polyfluorinted phenyl groups, 1,1-bis[4-(2,3-epoxypropoxy)phenyl]-1-(3,4,5-trifluorophenyl) -2,2,2-trifluoroethane (6FEP) was synthesized and characterized. The reactivtiy of 6FEP with two aromatic diamines, 4,4′-diaminodiphenyl methane (DDM) and 1,4-bis(4-amino-2-trifluoromethylphenoxy) benzene (6FAPB), and the properties of the cured 6FEP were investigated and compared with those of the commonly used epoxy resin diglycidyl ether of bisphenol A (DGEBA). The experimental results indicated that 6FEP showed lower reactivity than DGEBA. The cured 6FEP exhibited good thermal stabilities with decomposition temperature at 5% weight loss of 374–397°C, high glass transition temperature of 159–177°C and good mechanical properties. The cured 6FEP epoxy resin also showed low dielectric constants at 1 MHz in the range of 3.2–3.4 and dielectric dissipation factors (tan δ) in the range of 2.10–2.48 × 10−3. Moreover, the cured 6FEP epoxy resins exhibited higher surface hydrophobicity and lower moisture absorption compared with DGEBA. The improved dielectric properties and hydrophobic properties of the cured 6FEP epoxy resin could be attributed to the introduction of trifluoromethyl and pendant polyfluorinated phenyl groups into the molecular structure of the epoxy resin.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Chin-Ping Yang ◽  
Sheng-Huei Hsiao ◽  
Yu-Yang Su ◽  
Chun-Hung Lin ◽  
Mei-Yuan Hsu

AbstractA series of novel fluorinated poly(ether imide)s (PEIs) IVa-h were synthesized from 4,4’-(2,5-tolylenedioxy)diphthalic anhydride (I) and various trifluoromethyl-substituted aromatic bis(ether amine)s (IIa-h) via a conventional two-step method with thermal or chemical imidization of the precursor poly(amic acid)s. These PEIs were readily soluble in a variety of organic solvents; they were soluble with a concentration higher than 10% in amide-type polar solvents, ether type solvents, and chlorinated hydrocarbons. The solution-cast films showed a high optical transparency and low color intensity, with an ultraviolet-visible absorption edge of 371- 377 nm and low b* values (a yellowness index) of 4.9-7.5. These films were strong and tough with tensile strength of 90-103 MPa. They exhibited glass-transition temperatures (Tg) in the range of 207-293oC, with 10% weight loss temperature in excess of 500oC in air or nitrogen atmosphere. They also showed low-dielectric constants (2.95-3.37 at 1 MHz) and low moisture absorption (0.20- 0.67 wt %).


2018 ◽  
Vol 31 (5) ◽  
pp. 485-496 ◽  
Author(s):  
Xiao-Lan Zhang ◽  
Xiao-Ling Liu ◽  
Qiu-Ying Wang ◽  
Zhen-Zhong Huang ◽  
Shou-Ri Sheng

4-(4-Trifluoromethylphenyl)-2,6-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]pyridine (9FPBAPP), as a new aromatic diamine, was prepared by a modified Chichibabin reaction of 4-(4-nitro-2-trifluoromethylphenoxy)acetophenone with 4-triflouromethylbenzaldehyde, followed by a catalytic reduction. A series of fluorinated poly(ether imide)s containing pyridine and/or phenylphosphine oxide moieties were prepared from bis(3-aminophenyl)phenylphosphine oxide (BAPPO), 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), and 9FPBAPP via a conventional two-step thermal imidization procedure with various mole ratios of BAPPO and 9FPBAPP. All the polymers were amorphous and soluble in common organic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone and had Tg’s of 277–285°C, 5% weight loss temperature of 521–550°C in nitrogen. Furthermore, high char yields and good limited oxygen index values indicated that these polymers exhibited good thermal stability and flame-retardant property. Tough and flexible polymer films also had good mechanical properties with tensile strengths of 75–99 MPa, tensile moduli of 1.1–1.6 GPa, and elongations at break of 12%–24% and low dielectric constants of 2.81–3.53 (1 MHz), as well as high optical transparency with the ultraviolet cutoff wavelength in the range of 350–384 nm.


1994 ◽  
Vol 9 (2) ◽  
pp. 266-269 ◽  
Author(s):  
Chung-Hsin Lu ◽  
Nobuyasu Mizutani

Pyrochlore-type Pb2FeWO6.5 is difficult to be sintered without applied pressure at temperatures lower than its decomposition temperature. Through hot pressing or hot isostatic pressing processes, densification of specimens is greatly enhanced; moreover, grain growth during sintering is effectively suppressed. Densified Pb2FeWO6.5 exhibits paraelectric characteristic from −135°to −2 °C with low dielectric constants and low dissipation factors. The dielectric constants show rather weak dependence of temperature and frequency.


Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1499
Author(s):  
In-Ho Song ◽  
Dong-Min Kim ◽  
Ju-Young Choi ◽  
Seung-Won Jin ◽  
Kyeong-Nam Nam ◽  
...  

Pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) oligoimide particles and PMDA-ODA poly(amic acid) salt (PAAS) were synthesized and used as stabilizers to prepare oil-in-water Pickering high internal phase emulsions (HIPEs). The stability of the Pickering HIPEs was investigated by dispersion stability analysis. Polyimide-based polyHIPEs could be prepared through freeze-drying and subsequent thermal imidization of the Pickering HIPEs. The characteristics of the polyHIPEs, including their morphology, porosity, thermal decomposition temperature, and compression modulus, were investigated. The thermal decomposition temperature (T10) of the polyHIPEs was very high (>530 °C), and their porosity was as high as 92%. The polyimide-based polyHIPEs have the potential to be used in high-temperature environments.


1998 ◽  
Vol 10 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Yuvraj Singh Negi ◽  
Yoshi-Ichi Suzuki ◽  
Ichiro Kawamura ◽  
Masa-Aki Kakimoto ◽  
Yoshio Imai

Aromatic polyamide-imides having hexafluoroisopropylidene and isopropylidene groups in the main chain of the polymer were prepared by reacting 4-chloroformylphthalic anhydride (CPA) and fluorine or non-fluorine containing diamines using low-temperature polycondensation. Polyamide-imides were obtained with high molecular weight and high yield. Thermal decomposition temperature and glass transition temperatures of polymers were above 460 °C and 275 °C respectively. Fluorine and non-fluorine containing polyamide-imides were cast into transparent films which were characterized by mechanical and water absorption analysis.


2012 ◽  
Vol 581-582 ◽  
pp. 297-300
Author(s):  
Yun Hua Lu ◽  
Bing Wang ◽  
Guo Yong Xiao ◽  
Zhi Zhi Hu

Firstly, 1,4-bis(3-nitro-5-trifluoromethylphenoxy)benzene(I) was synthesized through the nucleophilic substitution reaction of 3,5-dinitrobenzotrifluoride and 1,4-dihydroxybenzene in the presence of potassium carbonate. Then, the diamine monomer 1,4-bis(3-amino-5-trifluoromethylphenoxy)benzene (II) was obtained through the catalytic reduction with hydrazine and Pd/C. These fluorinated polyimides (PI) were synthesized from the fluorinated diamine II with four kinds of dianhydrides, including pyromellitic dianhydride (PMDA), 3,3’,4,4’-biphenyltetracarboxylic acid dianhydride (BPDA), 3,3’,4,4’-oxydiphthalic anhydride (ODPA) and 3,3’,4,4’-benzophenonetetracarboxylicdianhydride (BTDA) respectively, via thermal imidization of poly(amic acid) (PAA). The structure and properties of these obtained fluorinated PIs were characterized. These experimental results showed that these fluorinated PI films exhibited excellent optical transmittance in the visible region and thermal resistance. The PI derived from ODPA showed the best optical transparency with the transmittance higher than 85.38 % at 450 nm. These PIs also exhibited good thermal properties with 5 wt% thermal decomposition temperature above 533 °C.


2011 ◽  
Vol 233-235 ◽  
pp. 1636-1641
Author(s):  
Hong Qiang Yan ◽  
Hua Qing Wang ◽  
Jie Cheng ◽  
Zheng Ping Fang

To obtain attractive properties, such as increased resistance to moisture absorption, low dielectric constant and low dielectric loss, the novel bismaleimide, viz. 2,7-bis(4-maleimidophenoxy) naphthalene (BMPN), and dicyanate ester, viz. 2,7-dihydroxynaphthalene dicyanate (DNCY), containing naphthalene ring and ether linkages, have been synthesized. The cure process of the blends including of 0.11mmol/mol Fe(AcAc)3 and 2% nonylphenol is characterized by in-situ FTIR. The result obtained from in-situ FTIR spectra of cured resin illuminates that the cure reaction is homo-polymerized respectively at this condition for the mixtures of B1C1. Interlaced network patterns are seen obviously and no visible phase separation could be detected in the region for IPNs BT resin by SEM. The structure of IPNs can be formed for the blends of BMPN and DNCY containing 0.11 mmol/mol Fe(AcAc)3 and 2% nonylphenol, which is tested by in-situ FTIR and SEM methods. The glass fiber reinforced composites for this blends are made and their properties are studied. This composites show good flexural property, low dielectric constants ( Dk ) and low moisture absorption.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1886
Author(s):  
Yan Zhang ◽  
Bo-han Wu ◽  
Han-li Wang ◽  
Hao Wu ◽  
Yuan-cheng An ◽  
...  

Optically transparent polyimide (PI) films with good dielectric properties and long-term sustainability in atomic-oxygen (AO) environments have been highly desired as antenna substrates in low earth orbit (LEO) aerospace applications. However, PI substrates with low dielectric constant (low-Dk), low dielectric dissipation factor (low-Df) and high AO resistance have rarely been reported due to the difficulties in achieving both high AO survivability and good dielectric parameters simultaneously. In the present work, an intrinsically low-Dk and low-Df optically transparent PI film matrix, poly[4,4′-(hexafluoroisopropylidene)diphthalic anhydride-co-2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane] (6FPI) was combined with a nanocage trisilanolphenyl polyhedral oligomeric silsesquioxane (TSP-POSS) additive in order to afford novel organic–inorganic nanocomposite films with enhanced AO-resistant properties and reduced dielectric parameters. The derived 6FPI/POSS films exhibited the Dk and Df values as low as 2.52 and 0.006 at the frequency of 1 MHz, respectively. Meanwhile, the composite films showed good AO resistance with the erosion yield as low as 4.0 × 10−25 cm3/atom at the exposure flux of 4.02 × 1020 atom/cm2, which decreased by nearly one order of magnitude compared with the value of 3.0 × 10−24 cm3/atom of the standard PI-ref Kapton® film.


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