Organosoluble and light‐colored fluorinated polyimides based on 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane and aromatic dianhydrides

A novel fluorinated diamine monomer, 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane (2), was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride with 2,2‐bis(4‐hydroxyphenyl)propane in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides were synthesized from diamine 2 and various aromatic dianhydrides 3a–f via thermal imidization. These polymers had inherent viscosities ranging from 0.73 to 1.29 dL/g. Polyimides 5a–f were soluble in amide polar solvents and even in less polar solvents. These films had tensile strengths of 87–100 MPa, elongations to break of 8–29%, and initial moduli of 1.7–2.2 GPa. The glass transition temperatures (T_g) of 5a–f were in the range of 222–271°C, and the 10% weight loss temperatures (T₁₀) of them were all above 493°C. Compared with polyimides 6 series based on 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane (BAPP) and polyimides 7 based on 2,2‐Bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane (6FBAPP), the 5 series showed better solubility and lower color intensity, dielectric constant, and lower moisture absorption. Their films had cutoff wavelengths between 363 and 404 nm, b* values ranging from 8 to 62, dielectric constants of 2.68–3.16 (1 MHz), and moisture absorptions in the range of 0.04–0.35 wt %. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 922–935, 2005     

Light‐colored fluorinated polyimides based on 2,5‐bis(4‐amino‐2‐trifluoromethylphenoxy)biphenyl and various aromatic dianhydrides

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     

Organosoluble and light‐colored fluorinated polyimides derived from 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy) phenyl]‐4,7‐methanohexahydroindan

A novel bis(ether amine) monomer, 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]‐4,7‐methanohexahydroindan ( 2 ), was synthesized through the nucleophilic aromatic substitution reaction of 5,5′‐bis‐(4‐hydroxyphenyl)‐4,7‐methanohexahydroindan with 2‐chloro‐5‐nitrobenzotrifluoride to yield the intermediate dinitro compound, followed by catalytic reduction with hydrazine and Pd/C. A series of polyimides were synthesized from 2 and various aromatic dianhydrides using a standard two‐stage process with chemical or thermal imidization of poly(amic acid). All of these polymer films were soluble in amide‐type solvents above 10% w/v, had tensile strengths of 97–117 MPa, and the 10% weight loss temperature was above 464 °C with their residues exceeding 46% at 800 °C in nitrogen. Compared with the non‐fluorinated polyimides, the fluorinated series were observed to have lower dielectric constants (2.92–3.28 at 1 MHz) and lower moisture absorptions (0.15–0.43 wt%) as well as lower color intensity and better solubility. Copyright © 2006 Society of Chemical Industry     

Organosoluble,low‐dielectric‐constant fluorinated polyimides based on 9,9‐bis[4‐(4‐amino‐2‐trifluoromethyl‐ phenoxy)phenyl]xanthene

A new trifluoromethylated bis(ether amine) monomer, 9,9‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]xanthene (BATFPX), was prepared through the nucleophilic aromatic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 9,9‐bis(4‐hydroxyphenyl)xanthene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of novel fluorinated polyimides were synthesized from BATFPX with various commercially available aromatic tetracarboxylic dianhydrides by one‐step polycondensation in m‐cresol. The resulting polyimides were readily soluble in many organic solvents such as N,N‐dimethylacetamide and tetrahydrofuran, and afforded transparent, flexible and strong films with low moisture absorption (0.28–0.51%), low dielectric constant (2.85–3.26 at 1 MHz) and good optical transparency with UV‐visible absorption cut‐off wavelengths at 352–410 nm. All the polyimides were amorphous and exhibited high thermal stability, with glass transition temperatures of 282–330 °C, 5% weight loss temperatures above 520 °C in nitrogen or air and char yields higher than 55% at 800 °C in nitrogen. Also, these polyimides had good mechanical properties with tensile strengths of 93–118 MPa, elongations at break of 9–16% and initial moduli of 2.07–2.58 GPa. Copyright © 2011 Society of Chemical Industry     

Synthesis and characterization of ternary‐copolymer of soluble fluorinated polyimides based on 1,4‐bis (4‐amino‐2‐trifluoromethylphenoxy) benzene

A series of novel ternary‐copolymer of fluorinated polyimides (PIs) were prepared from 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene (pBATB), commercially available aromatic dianhydrides, and aromatic diamines via a conventional two‐step thermal or chemical imidization method. The structures of all the obtained PIs were characterized with FTIR, ¹H‐NMR, and element analysis. Besides, the solubility, thermal stability, mechanical properties, and moisture uptakes of the PIs were investigated. The weight‐average molecular weight (M_w) and the number‐average molecular weight (M_n) of the PIs were determined using gel‐permeation chromatography (GPC). The PIs were readily dissolved not only in polar solvents such as DMF, DMAc, and NMP, but also in some common organic solvents, such as acetic ester, chloroform, and acetone. The glass transition temperatures of these PIs ranged from 201 to 234°C and the 10% weight loss temperatures ranged from 507 to 541°C in nitrogen. Meanwhile, all the PIs left around 50% residual even at 800°C in nitrogen. The GPC results indicated that the PIs possessed moderate‐to‐high number‐average molecular weight (M_n), ranging from 9609 to 17,628. Moreover, the polymer films exhibited good mechanical properties, with elongations at break of 8–21%, tensile strength of 66.5–89.8 MPa, and Young's modulus of 1.04–1.27 GPa, and low moisture uptakes of 0.54–1.13%. These excellent combination properties ensure that the polymer could be considered as potential candidates for photoelectric and microelectronic applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Organosoluble,low‐dielectric‐constant fluorinated polyimides based on 2,6‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene

A novel fluorinated bis(ether amine) monomer, 2,6‐bis(4‐amino‐2‐trifluoromethylphenoxy) naphthalene, was prepared through the nucleophilic aromatic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 2,6‐dihydroxynaphthalene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of novel trifluoromethylated polyimides were synthesized from the diamine with various commercially available aromatic tetracarboxylic dianhydrides using a two‐stage process with thermal imidization of poly(amic acid) films. Most of 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 (T_gs) of 249–311 °C, high thermal stability and good mechanical properties. Low moisture (0.19–0.85 %), low dielectric constants (2.49–3.59 at 10 kHz), and low color intensity were also observed. For a comparative study, a series of analogous polyimides based on 2,6‐bis(4‐aminophenoxy)naphthalene were also prepared and characterized. Copyright © 2005 Society of Chemical Industry     

Novel organosoluble poly(amide‐imide‐imide)s synthesized from new tetraimide‐dicarboxylic acid by condensation with 4,4′‐oxydiphthalic anhydride, 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene,trimellitic anhydride,and various aromatic diamines

A new monomer of tetraimide‐dicarboxylic acid (IV) was synthesized by starting from ring‐opening addition of 4,4′‐oxydiphthalic anhydride, trimellitic anhydride, and 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene at a 1:2:2 molar ratio in N‐methyl‐2‐pyrrolidone (NMP). From this new monomer, a series of novel organosoluble poly(amide‐imide‐imide)s with inherent viscosities of 0.7–0.96 dL/g were prepared by triphenyl phosphite activated polycondensation from the tetraimide‐diacid with various aromatic diamines. All synthesized polymers were readily soluble in a variety of organic solvents such as NMP and N,N‐dimethylacetamide, and most of them were soluble even in less polar m‐cresol and pyridine. These polymers afforded tough, transparent, and flexible films with tensile strengths ranging from 99 to 125 MPa, elongations at break from 12 to 19%, and initial moduli from 1.6 to 2.4 GPa. The thermal properties and stability were also good with glass‐transition temperatures of 236–276°C and thermogravimetric analysis 10 wt % loss temperatures of 504–559°C in nitrogen and 499–544°C in air. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2854–2864, 2006     

Synthesis and characterization of readily soluble polyarylates derived from either 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane or tetramethylbisphenol A and aromatic diacid chlorides

A series easily soluble polyarylates were synthesized from either 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane or tetramethylbisphenol A with various aromatic diacid chlorides by the two‐phase interfacial polycondensation. These polyarylates have the inherent viscositiesin the range of 0.36–0.97 dL/g, and their number‐average and weight‐average molecular weights determined by gel permeation chromatography are 14,200–43,200 and 31,900–102,500, respectively. All these polyarylates are readily soluble in a wide range of organic solvents, thus these polymers can be convenient to process into heat resistance films by cast, spin‐ or dip‐coating. The polyarylates have the glass transition temperatures in the range of 165.0–201.6°C. The pendent phenyl‐containing polyarylates reveal excellent thermal stability, and their initial degradation temperatures are all above 480°C and char yields at 700°C are 37.97–40.53% in nitrogen atmosphere. However, the polymers prepared from tetramethylbisphenol A have a large decrease in thermal stability, and their initial degradation temperatures in nitrogen are only about 440°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of new cardo poly(ether imide)s derived from 9,9‐bis [4‐(4‐aminophenoxy)phenyl]xanthene

A series of new cardo poly(ether imide)s bearing flexible ether and bulky xanthene pendant groups was prepared from 9,9‐bis[4‐(4‐aminophenoxy)phenyl]xanthene with six commercially available aromatic tetracarboxylic dianhydrides in N,N‐dimethylacetamide (DMAc) via the poly(amic acid) precursors and subsequent thermal or chemical imidization. The intermediate poly(amic acid)s had inherent viscosities between 0.83 and 1.28 dL/g, could be cast from DMAc solutions and thermally converted into transparent, flexible, and tough poly(ether imide) films which were further characterized by X‐ray and mechanical analysis. All of the poly(ether imide)s were amorphous and their films exhibited tensile strengths of 89–108 MPa, elongations at break of 7–9%, and initial moduli of 2.12–2.65 GPa. Three poly(ether imide)s derived from 4,4′‐oxydiphthalic anhydride, 4,4′‐sulfonyldiphthalic anhydride, and 2,2‐bis(3,4‐dicarboxyphenyl))hexafluoropropane anhydride, respectively, exhibited excellent solubility in various solvents such as DMAc, N,N‐dimethylformamide, N‐methyl‐2‐pyrrolidinone, pyridine, and even in tetrahydrofuran at room temperature. The resulting poly(ether imide)s with glass transition temperatures between 286 and 335°C had initial decomposition temperatures above 500°C, 10% weight loss temperatures ranging from 551 to 575°C in nitrogen and 547 to 570°C in air, and char yields of 53–64% at 800°C in nitrogen. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and properties of fluorinated polyimides from 1,1‐bis(4‐amino‐3,5‐dimethylphenyl)‐1‐(3,4,5‐trifluorophenyl)‐2,2,2‐trifluoroethane and various aromatic dianhydrides

A novel aromatic diamine, 1,1‐bis(4‐amino‐3,5‐dimethylphenyl)‐1‐(3,4,5‐trifluorophenyl)‐2,2,2‐trifluoroethane, containing a pendant polyfluorinated phenyl group, a trifluoromethyl group, and methyl groups ortho‐substituted to the amino groups in the structure was synthesized and characterized. The diamine was polymerized with several aromatic dianhydrides, including 3,3′,4,4′‐biphenyltetracarboxylic dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride, 4,4′‐oxydiphthalic anhydride, and 4,4′‐hexafluoroisopropylidene diphthalic anhydride, via a high‐temperature one‐step procedure to afford four polyimides (PIs) with inherent viscosities of 0.47–0.70 dL/g. The PIs exhibited excellent solubilities in a variety of organic solvents. They were soluble not only in polar aprotic solvents but in many common solvents, such as cyclopentanone, tetrahydrofuran, and even toluene at room temperature. The tough and flexible PI films cast from the PI solutions exhibited good thermal stabilities and acceptable tensile properties. The glass‐transition temperatures were in the range 312–365°C, and the 5% weight loss temperatures were all higher than 480°C in nitrogen. The films had tensile strengths in the range 76–99 MPa, tensile moduli of 2.2–2.8 GPa, and elongations at break of 5–8%. In addition, the PI films exhibited excellent transparency in the visible light region with cutoff wavelength as low as 302 nm and transmittance higher than 88% at the wavelength of 450 nm. The PI films showed low dielectric constants ranging from 2.50–2.68 and low moisture absorptions of less than 0.56%. The good combined properties of the PIs mainly resulted from the synergic effects of the different substituents. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Organosoluble and Light-colored Fluorinated Polyimides from 2,2-Bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]sulfone and Aromatic Dianhydrides

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%.     

Synthesis and characterization of novel soluble pyridine‐containing polyimides based on 4‐phenyl‐2,6‐bis[4‐(4‐aminophenoxy)phenyl]‐pyridine and various aromatic dianhydrides

A new kind of pyridine‐containing aromatic diamine monomer, 4‐phenyl‐2,6‐bis[4‐(4‐aminophenoxy)phenyl]‐pyridine (PAPP), was successfully synthesized by a modified chichibabin reaction of benzaldehyde and a substituted acetophenone, 4‐(4‐nitrophenoxy)‐acetophenone (NPAP), followed by a reduction of the resulting dinitro compound 4‐phenyl‐2,6‐bis[4‐(4‐nitrophenoxy)phenyl]‐pyridine (PNPP) with Pd/C and hydrazine monohydrate. The aromatic diamine was employed to synthesize a series of new pyridine‐containing polyimides by polycondensation with various aromatic dianhydrides in N‐methy‐2‐pyrrolidone (NMP) via the conventional two‐step method, i.e., ring‐opening polycondensation forming the poly (amic acid)s and further thermal or chemical imidization forming polyimides. The inherent viscosities of the resulting polyimides were in the range of 0.79–1.13 dL/g, and most of them were soluble in common organic solvents such as N,N‐dimethylacetamide (DMAc), NMP, and tetrahydrofuran (THF), etc. Meanwhile, strong and flexible polyimide films were obtained, which had good thermal stability, with the glass transition temperatures (T_g) of 268–338°C and the temperature at 5% weight loss of 521–548°C in air atmosphere, as well as outstanding mechanical properties with tensile strengths of 89.2–112.1 MPa and elongations at break of 9.5–15.4%. The polyimides also were found to possess low dielectric constants ranging from 2.53 to 3.11. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 212–219, 2007     

Processable and colorless fluorinated poly(ether imide)s based on an isopropylidene‐containing bis(ether anhydride) and various aromatic bis(ether amine)s bearing trifluoromethyl groups

A series of novel organosoluble and light‐colored fluorinated poly(ether imide)s (PEIs) ( IV ) having inherent viscosities of 0.43–0.59 dL/g were prepared from 4,4′‐[1,4‐phenylenbis(isopropylidene‐1,4‐phenyleneoxy)]diphthalic anhydride ( I ) and various trifluoromethyl‐substituted aromatic bis(ether amine)s by a standard two‐step process with thermal and chemical imidization of poly(amic acid) precursors. These PEIs showed excellent solubility in many organic solvents and could be solution‐cast into transparent and tough films. These films were essentially colorless, with an UV–visible absorption edge of 361–375 nm and a very low b* value (a yellowness index) of 15.3–17.0. They also showed good thermal stability with glass‐transition temperature of 191–248°C, 10% weight loss temperature in excess of 494°C, and char yields at 800°C in nitrogen more than 39%. The thermally cured PEI films showed good mechanical properties with tensile strengths of 83–96 MPa, elongations at break of 8–11%, and initial moduli of 1.7–2.0 GPa. They possessed lower dielectric constants of 3.25–3.72 (1 MHz). In comparison with the V series nonfluorinated PEIs, the IV series showed better solubility, lower color intensity, and lower dielectric constants. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 620–628, 2007     

Preparation and properties of polyimides based on bis[3,5‐dimethyl‐4‐(4‐aminophenoxy)phenyl]methane

A series of polyimide (PI) thin films were synthesized based on bis[3,5‐dimethyl‐4‐(4‐aminophenoxy)phenyl]methane and conventional aromatic dianhydrides. The structures and properties of the thin films were measured with Fourier transform infrared, NMR, thermogravimetric analysis, dynamic mechanical analysis, and impedance analysis. The PI films exhibited glass‐transition temperatures in the range of 211–300°C and possessed initial thermal decomposition temperature reaching up to 457–482°C in air and 461–473°C in nitrogen. Some PI films had high solubility in organic solvents such as 1‐methyl‐2‐pyrrolidinone, N,N‐dimethylformamide, N,N‐dimethylacetamide, dimethyl sulfoxide, m‐cresol, tetrahydrofuran, and CHCl₃. The mechanical properties of these films were also examined. The dielectric constants of the films were in the range of 2.8–3.3 at 25°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1265–1270, 2007     

The preparation of α‐bis and α,ω‐tetrakis aromatic oxazolyl‐ and carboxyl‐functionalized polymers using 1,1‐bis[4‐(2‐(4,4‐dimethyl‐1,3‐oxazolyl))phenyl]ethylene in atom transfer radical polymerization reactions

The preparation of new compounds, 1,1‐bis[4‐(2‐(4,4‐dimethyl‐1,3‐oxazolyl))phenyl]ethanol and a new symmetrically disubstituted 1,1‐diphenylethylene derivative, 1,1‐bis[4‐(2‐(4,4‐dimethyl‐1,3‐oxazolyl))phenyl]ethylene, is described. 1,1‐Bis[4‐(2‐(4,4‐dimethyl‐1,3‐oxazolyl))phenyl]ethylene was utilized as a dioxazolyl initiator precursor for the polymerization of styrene by atom transfer radical polymerization (ATRP) methods to produce α‐bis(oxazolyl) polystyrene. The kinetic study of the polymerization process indicated that the free radical polymerization reaction for the preparation of α‐bis(oxazolyl) polystyrene follows first‐order rate kinetics with respect to monomer consumption. α,ω‐Tetrakis(oxazolyl) polystyrene was prepared by a new, in situ, controlled/living, post‐ATRP chain‐end‐functionalization reaction which involves the direct addition of 1,1‐bis[4‐(2‐(4,4‐dimethyl‐1,3‐oxazolyl))phenyl]ethylene to the ω‐terminus of the α‐bis(oxazolyl) polystyrene derivative, without the isolation and purification of the polymeric precursor. α‐Bis(carboxyl) and α,ω‐tetrakis(carboxyl) polystyrene derivatives were obtained by the quantitative chemical transformation of the oxazoline groups of the respective aromatic oxazolyl chain‐end‐functionalized polystyrene derivatives to the aromatic carboxyl groups. The organic precursor compounds, the dioxazolyl‐functionalized 1,1‐diphenylethylene derivative and the functionalized polymers were characterized using ¹H NMR and ¹³C NMR spectrometry and Fourier transform infrared spectroscopy, size‐exclusion and thin‐layer chromatography and non‐aqueous titration measurements. © 2014 Society of Chemical Industry     

Synthesis and properties of organosoluble polyimides based on 1,1-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]cyclohexane

New aromatic diamine with cyclohexane cardo group substituted with trifluoromethyl group in the side chain, 1,1-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]cyclohexane (II), was prepared through the nucleophilic substitution reaction of 1,1-bis(4-hydroxyphenyl)cyclohexane and 2-chloro-5-nitrobenzotrifluoride in the presence of potassium carbonate, to yield the intermediate dinitro compound I, followed by catalytic reduction with hydrazine and Pd/C to afford the diamine II. Fluorinated polyimides (IVa-g) were prepared from the II with various aromatic dianhydrides via thermal or chemical imidization of poly(amic acid). These polyimides had inherent viscosity ranging from 0.72 to 1.16 dl/g and showed excellent solubility in a variety of organic solvents. They were soluble in a concentration of 10% in the amide polar solvent, and 1-5% in the other testing solvents. IV films showed good mechanical properties, excellent thermal stability. The 10% weight loss temperature was above 476 °C in nitrogen or air, and the glass transition temperature was recorded at 214-278 °C. In comparison of the IV series with the analogous nonfluorinated polyimides (V series) based on 1,1-bis[4-(4-aminophenoxy)phenyl]cyclohexane (II′), IV series revealed better solubility, lighter-colored and lower dielectric constants and moisture absorptions. Their films had cut-off wavelengths in the range of 364-414 nm, b^* value (a yellowness index) ranging from 3.3 to 66.3, dielectric constants of 3.02-3.55 (1 MHz), with moisture absorption of 0.16-0.36 wt%.     

Synthesis and characterization of new cardo poly(bisbenzothiazole)s from 1,1‐bis(4‐amino‐3‐mercaptophenyl)‐4‐tert‐butylcyclohexane dihydrochloride

A new monomer 1,1‐bis(4‐amino‐3‐mercaptophenyl)‐4‐tert‐butylcyclohexane dihydrochloride, bearing the bulky pendant 4‐tert‐butylcyclohexylidene group, was synthesized from 4‐tert‐butylcyclohexanone in three steps. Its chemical structure was characterized by ¹H NMR, ¹³C NMR, MS, FTIR, and EA. Aromatic poly(bisbenzothiazole)s (PBTs V) were prepared from the new monomer and five aromatic dicarboxylic acids by direct polycondensation. The inherent viscosities were in the range of 0.63–2.17 dL/g. These polymers exhibited good solubility and thermal stability. Most of the prepared PBTs V were soluble in various polar solvents. Thermogravimetric analysis showed the decomposition temperatures at 10% weight loss that were in the range of 495–534°C in nitrogen. All the PBTs V, characterized by X‐ray diffraction, were amorphous. The UV absorption spectra of PBTs V showed a range of λ_max from 334 to 394 nm. All the PBTs V prepared had evident fluorescence emission peaks, ranging from 423 to 475 nm with different intensity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2000–2008, 2006     

Synthesis and properties of fluorinated aromatic poly(amide imide)s based on 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone and various bis(trimellitimide)s

A CF₃‐containing diamine, 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone ( 2 ), was synthesized from 4,4′‐dihydroxybenzophenone and 2‐chloro‐5‐nitrobenzotrifluoride. Imide‐containing diacids ( 3 and 5B_a – 5B_g ) were prepared by the condensation reaction of aromatic diamines and trimellitic anhydride. Then, two series of novel soluble aromatic poly(amide imide)s (PAIs; 6A_a – 6A_k and 6B_a – 6B_g ) were synthesized from a diamine ( 4A_a – 4A_k or 2 ) with the imide‐containing diacids ( 3 and 5B_a – 5B_g ) via direct polycondensation with triphenyl phosphate and pyridine. The aromatic PAIs had inherent viscosities of 0.74–1.76 dL/g. All of the synthesized polymers showed excellent solubility in amide‐type solvents, such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylacetamide (DMAc), and afforded transparent and tough films by DMAc solvent casting. These polymer films had tensile strengths of 90–113 MPa, elongations at break of 8–15%, and initial moduli of 2.0–2.9 GPa. The glass‐transition temperatures of the aromatic PAIs were in the range 242–279°C. They had 10% weight losses at temperatures above 500°C and showed excellent thermal stabilities. The 6B series exhibited less coloring and showed lower yellowness index values than the corresponding 6A series. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3641–3653, 2006     

Synthesis and properties of polyamides based on 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan

A new diamine 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan ( 3 ) was prepared through the nucleophilic displacement of 5,5′‐bis(4‐hydroxylphenyl)‐hexahydro‐4,7‐methanoindan ( 1 ) with p‐halonitrobenzene in the presence of K₂CO₃ in N,N‐dimethylformamide (DMF), followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new polyamides were synthesized by the direct polycondensation of diamine 3 with various aromatic dicarboxylic acids. The polymers were obtained in quantitative yields with inherent viscosities of 0.76–1.02 dl g⁻¹. All the polymers were soluble in aprotic dipolar solvents such as N,N‐dimethylacetamide (DMAc) and N‐methyl‐2‐pyrrolidone (NMP), and could be solution cast into transparent, flexible and tough films. The glass transition temperatures of the polyamides were in the range 245–282 °C; their 10% weight loss temperatures were above 468 °C in nitrogen and above 465 °C in air. © 2000 Society of Chemical Industry     

Synthesis of soluble and thermally stable polyimides from 3,5‐diamino‐N‐(4‐(8‐quinolinoxy) phenyl) aniline and various dianhydrides

Three novel polyimides (PIs) having pendent 4‐(quinolin‐8‐yloxy) aniline group were prepared by polycondensation of a new diamine with commercially available tetracarboxylic dianhydrides, such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs were characterized by FTIR, ¹H NMR, and elemental analysis; they had high yields with inherent viscosities in the range of 0.4–0.5 dl g⁻¹, and exhibited excellent solubility in many organic solvents such as N,N‐dimethyl acetamide, N,N′‐dimethyl formamide, N‐methyl pyrrolidone (NMP), dimethyl sulfoxide, and pyridine. These PIs exhibited glass transition temperatures (T_g) between 250 and 325° C. Their initial decomposition temperatures (T_i) ranged between 270 and 450°C, and 10% weight loss temperature (T₁₀) up to 500°C with 68% char yield at 600°C under nitrogen atmosphere. Transparent and hard polymer films were obtained via casting from their NMP solutions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011