Oligomeric bisphenol A‐based PEEK‐like phthalonitrile‐cure and polymer properties

The cure behavior and properties of oligomeric bisphenol A‐based PEEK‐like phthalonitrile (PN) are thoroughly examined in this article. The resin is easily processed from the melt at a relatively low temperature (150–200 °C) and the monomer cure occurs in a controlled manner as a function of the amine content and processing thermal conditions. Dynamic mechanical measurements and thermogravimetric analysis show that the polymer properties improve as the maximum PN postcure temperature is increased to 415 °C. The effects of the amine and polymer postcure conditions on the flexural and tensile properties of the PN polymer are investigated. The mechanical properties of the polymer are maximized after postcuring to moderate temperatures (330–350 °C). The polymer exhibits an average flexural strength and tensile strength at break of 117 and 71 MPa, respectively. After oxidative aging at 302 °C for 100 h, the polymer retains excellent mechanical properties. The average flexural and tensile strength retention of the polymers are 81 and 75%, respectively. Microscale calorimetric measurements reveal that the flammability parameters of the oligomeric PN are low compared to other thermosets. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3769–3777     

Synthesis and properties of aromatic polyamides derived from 2,6-bis(4-aminophenoxy)naphthalene and various aromatic dicarboxylic acids

2,6-Bis(4-aminophenoxy)naphthalene (2,6-BAPON) was synthesized in two steps from the condensation of 2,6-dihydroxynaphthalene with p-chloronitrobenzene in the presence of potassium carbonate, giving 2,6-bis(4-nitrophenoxy)naphthalene, followed by hydrazine hydrate/Pd—C reduction. A series of new polyamides were synthesized by the direct polycondensation of 2,6-BAPON with various aromatic dicarboxylic acids in the N-methyl-2-pyrrolidone (NMP) solution containing dissolved metal salts such as CaCl₂ or LiCl using triphenyl phosphite and pyridine as condensing agents. The polymers were obtained in quantitative yields with inherent viscosities of 0.62–2.50 dL/g. Most of the polymers were soluble in aprotic dipolar solvents such as N,N-dimethylacetamide (DMAc) and NMP, and they could be solution cast into transparent, flexible, and tough films. The casting films had yield strengths of 84–105 MPa, tensile strengths of 68–95 MPa, elongations at break of 8–36%, and tensile moduli of 1.4–2.1 GPa. The glass transition temperatures of the polyamides were in the range 155–225°C, and their 10% weight loss temperatures were above 505°C in nitrogen and above 474°C in air. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2147–2156, 1997     

Characterization of new natural cellulosic fiber from the Perotis indica plant

This investigation summarizes the characteristics of biofiber extracted from the Perotis indica plant. Cellulose content (68.4 wt%), density (785 kg m^?3), crystallinity index (48.3%), tensile strength (317–1,608 MPa), and Young’s modulus (8.41–69.61 GPa) properties were identified in the P. indica fibers (PIFs), and thermal stability was studied using thermal gravimetric analysis and derivative thermogravimetric analysis, which revealed its cellulose degradation at a temperature of 339.1°C. Further, the properties of PIFs ensured that it can play an imperative role as new reinforcement as green composites in the manufacturing industries.     

Synthesis and properties of aromatic polyamides derived from 1,6-bis(4-aminophenoxy)naphthalene and aromatic dicarboxylic acids

A new bis(phenoxy)naphthalene-containing diamine, 1,6-bis(4-aminophenoxy)naphthalene, was synthesized in two steps from the condensation of 1,6-dihydroxynaphthalene with p-chloronitrobenzene in the presence of potassium carbonate, giving 1,6-bis(4-nitrophenoxv)naphthalene, followed by hydrazine hydrate/Pd—C reduction. A series of polyamides were synthesized by the direct polycondensation of the diamine with various aromatic dicarboxylic acids in the N-methyl-2-pyrrolidone (NMP) solution containing dissolved metal salts such as CaCl₂ or LiBr using triphenyl phosphite and pyridine as condensing agents. The polymers were obtained in quantitative yield with inherent viscosities of 0.78–3.72 dL/g. Most of the polymers were soluble in aprotic solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), NMP, and they could be solution-cast into transparent, flexible and tough films. The casting films had tensile strength of 102–175 MPa, elongation at break of 8–42%, and tensile modulus of 2.4–3.8 GPa. The polymers derived from rigid dicarboxylic acids such as terephthalic acid and 4,4′-biphenyldicarboxylic acid exhibited some crystalline characteristics. The glass transition temperatures of the polyamides were in the range of 238–337°C, and their 10% weight loss temperatures were above 487°C in nitrogen and above 438°C in air. © 1995 John Wiley & Sons, Inc.     

Synthesis and characterization of norbornane-containing cardo polyamides

A new diamine, 2,2-bis[4-(4-aminophenoxy)phenyl]norbornane (BAPN), containing both ether and norbornane cardo groups, was synthesized in three steps started from norcamphor. A series of cardo polyamides were obtained by the direct polycondensation of BAPN and various aromatic dicarboxylic acids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. Polyamides had inherent viscosities in the range of 0.82–1.58 dL g⁻¹, and were readily soluble in polar aprotic solvents such as NMP, N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide and dimethyl sulfoxide. These polymers were cast in DMAc solution into transparent, flexible, and tough films that were further characterized by X-ray and mechanical analysis. All the polymers were amorphous, and the polyamide films had a tensile strength range of 71–89 MPa, an elongation at break range of 5–9%, and a tensile modulus range of 2.0–2.3 GPa. Polyamides showed glass transition temperatures in the range of 256–296°C as measured by DSC and thermogravimetric analysis indicated no weight loss below 450°C in nitrogen and air atmosphere. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2791–2794, 1999     

Poly(ether imide)s derived from phthalazinone‐containing dianhydrides

An unsymmetrical and noncoplanar heterocyclic dianhydride was synthesized from a bisphenol‐like phthalazinone, 4‐(4‐hydroxylphenyl)‐2,3‐phthalazin‐1‐one, and a series of novel poly(ether imide)s based on it, with intrinsic viscosities of 0.67–1.42 dL/g, were obtained by one‐step solution polymerization in m‐cresol at 200 °C for 20 h. The polymers were readily soluble in N‐methyl‐2‐pyrrolidinone and m‐cresol. The poly(ether imide)s derived from 4,4′‐oxydianiline and 4,4′‐methylenedianiline were also very soluble in chloroform, 1,1′,2,2′‐tetrachloroethane, and N,N‐dimethylacetamide. The glass‐transition temperatures were 289–326 °C, as determined by differential scanning calorimetry. All the degradation temperatures for 5% weight loss occurred above 482 °C in nitrogen. The tensile strength of thin films of some of the polymers varied from 103.1 to 121.4 MPa. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6089–6097, 2004     

Synthesis and properties of alternating copolyamide‐imides based on 2,6‐bis(4‐aminophenoxy)naphthalene and comparison with its related isomeric polymers

A series of novel polyamide‐imides III containing 2,6‐bis(phenoxy)naphthalene units were synthesized by 2,6‐bis(4‐aminophenoxy)naphthalene and various bis(trimellitimide)s in N‐methyl‐2‐pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents through direct polycondensation. The polymers were obtained in quantitative yield with inherent viscosities up to 1.53 dL/g. Most of the polymers showed good solubility in NMP, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide and could be solution‐cast into transparent, flexible, and tough films. The films had tensile strengths of 84–111 MPa, elongations at break of 8–33%, and initial moduli of 2.2–2.8 GPa. Wide‐angle X‐ray diffraction revealed that most polymers III were amorphous. The glass‐transition temperatures of some of the polymers could be determined by differential scanning calorimetry traces, recorded at 247–290 °C. The polyamide‐imides exhibited excellent thermal stabilities and had 10% weight loss at temperatures in the range of 501–575 °C under nitrogen atmosphere. They left more than 57% residue even at 800 °C in nitrogen. A comparative study of some corresponding polyamide‐imides is also presented. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2591–2601, 2001     

Synthesis and characterization of new soluble polyamides derived from 3,3′,5,5′-tetramethyl-2,2-bis[4-(4-carboxyphenoxy)phenyl]propane

A series of new soluble polyamides having isopropylidene and methyl-substituted arylene ether moieties in the polymer chain were prepared by the direct polycondensation of 3,3′,5,5′-tetramethyl-2,2-bis[4-(4-carboxyphenoxy)phenyl]propane and various diamines in N-methyl-2-pyrrolidinone (NMP) containing CaCl₂ using triphenyl phosphite and pyridine as condensing agents. Polymers were produced with moderate to high inherent viscosities of 0.85–1.47 dL g⁻¹ while the weight-average molecular weight and number-average molecular weight were in the range of 86,700–259,000 and 43,300–119,000, respectively. All the polymers were readily dissolved in polar aprotic solvents such as NMP, N,N-dimethylacetamide, and N,N-dimethylformamide, as well as less polar solvents such as m-cresol and pyridine, and even soluble in tetrahydrofuran. These polymers were solution-cast into transparent, flexible and tough films. All of the polymers were amorphous and the polyamide films had a tensile strength range of 82–122 MPa, an elongation at break range of 6–18%, and a tensile modulus range of 2.0–2.8 GPa. These polyamides had glass transition temperatures between 233–260°C and 10% weight loss temperatures in the range of 450–489 and 459–493°C in nitrogen and air atmosphere, respectively. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1997–2003, 1999     

Syntheses and properties of polyamides from ether diacid having the spirobichroman unit

A novel hexamethylspirobichroman (HMSBC) unit-containing dicarboxylic acid, 6,6′-bis(4-carboxyphenoxy)-4,4,4′,4′,7,7′-hexamethyl-2,2′-spirobichroman ( 3 ), was derived from nucleophilic substitution of p-fluorobenzonitrile with the phenolate ion of 6,6′-dihydroxy-4,4,4′,4′,7,7′-hexamethyl-2,2′-spirobichroman ( 1 ), followed by alkaline hydrolysis of the intermediate bis(ether nitrile). Using TPP and pyridine as condensing agents, a series of polyamides with inherent viscosities in the range of 0.82–1.14 dL/g were prepared by the direct polycondensation of dicarboxylic acid 3 with various aromatic diamines. All the obtained polymers were noncrystalline and soluble in various organic solvents such as N,N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP). Except for the polymer derived from benzidine, the other polyamides could be solution cast into transparent and tough films, and their tensile strengths, elongations at break, and tensile moduli were in the range of 56–76 MPa, 4–59%, and 1.6–2.0 GPa, respectively. These polyamides had glass transition temperatures in the range of 183–200°C with 10% weight loss above 420°C. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1479–1486, 1997     

Synthesis and properties of fluorinated polyimides. 1. Derived from novel 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl

A new diamine monomer, 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl (ATFT) was synthesized that led to a number of novel fluorinated polyimides by solution as well as thermal imidization routes when reacted with different commercially available dianhydrides like pyromellatic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), or 2,2‐bis(3,4‐dicarboxyphenyl) hexafluoropropane (6FDA). The polyimides ATFT/BTDA and ATFT/6FDA derived from both routes were soluble in several organic solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, and dimethyl sulfoxide. The polyimide ATFT/PMDA was only soluble in N‐methylpyrollidone. The polyimide films had low water absorption of 0.3–0.7%, low dielectric constants of 2.72–3.3 at 1 Hz, refractive indices of 1.594–1.647 at 589.3 nm, and optical transparency >85%. These polyimides showed very high thermal stability with decomposition temperatures (5% weight loss) up to 532 °C in air and good isothermal stability; only 7% weight loss occurred at 400 °C after 7 h, and less than 0.6% weight loss was observed at 315 °C for 5 h. Transparent thin films of these polyimides exhibited tensile strengths up to 112 MPa, a modulus of elasticity up to 3.05 GPa, and elongation at break up to 21% depending on the repeating unit structure. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1016–1027, 2002     

Synthesis and characterization of soluble aromatic polyurea-amides from new N,N′--dimethyl-N,N′-bis(aminophenyl)ureas and aromatic dicarboxylic acid chlorides

Aromatic polyurea-amides having inherent viscosities of 0.36–0.67 dL/g were synthesized by the low temperature solution polycondensation of new N,N′-dimethyl-N,N′-bis(aminophenyl)ureas with various aromatic dicarboxylic acid chlorides. All the polymers were amorphous, and most of them were soluble in a variety of organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide (DMAc), m-cresol, and pyridine. Some of the polymers could be cast from the DMAc solutions into transparent and flexible films having good tensile properties. The glass transition temperatures of the polyurea-amides obtained from the bis(4-aminophenyl)-substituted ureas were 244–272°C. The temperatures of 10% weight loss under nitrogen of the polymers were in the range of 430 and 480°C. © 1995 John Wiley & Sons, Inc.     

Synthesis and characterization of novel polyamide‐imides containing noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit

A new diimide‐dicarboxylic acid, 2,2′‐dimethyl‐4,4′‐bis(4‐trimellitimidophenoxy)biphenyl (DBTPB), containing a noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit was synthesized by the condensation reaction of 2,2′‐dimethyl‐4,4′‐bis(4‐minophenoxy)biphenyl (DBAPB) with trimellitic anhydride in glacial acetic acid. A series of new polyamide‐imides were prepared by direct polycondensation of DBAPB and various aromatic diamines in N‐methyl‐2‐pyrrolidinone (NMP), using triphenyl phosphite and pyridine as condensing agents. The polymers were produced with high yield and moderate to high inherent viscosities of 0.86–1.33 dL · g⁻¹. Wide‐angle X‐ray diffractograms revealed that the polymers were amorphous. Most of the polymers exhibited good solubility and could be readily dissolved in various solvents such as NMP, N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide (DMF), dimethyl sulfoxide, pyridine, cyclohexanone, and tetrahydrofuran. These polyamide‐imides had glass‐transition temperatures between 224–302 °C and 10% weight loss temperatures in the range of 501–563 °C in nitrogen atmosphere. The tough polymer films, obtained by casting from DMAc solution, had a tensile strength range of 93–115 MPa and a tensile modulus range of 2.0–2.3 GPa. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 63–70, 2001     

Synthesis and Characterization of New Soluble Polyamides from 9,9-Bis[4-(chloroformylphenoxy)phenyl]xanthene and Various Aromatic Diamines

9,9‐Bis(4‐hydroxyphenyl)xanthene (BHPX) was synthesized in 82% yield from xanthenone in a one‐pot, two‐step synthetic procedure. A new diacyl chloride monomer, 9,9‐bis[4‐(chloroformylphenoxy)phenyl]xanthene (BCPX), was synthesized in three steps from the nucleophilic fluorodisplacement of 4‐fluorobenzonitrile with the dipotassium bisphenolate of BHPX, followed by alkaline hydrolysis of the intermediate bis(ether nitrile), and then chlorination with thionyl chloride. Several novel aromatic polyamides containing ether and bulky xanthene groups with the inherent viscosities (0.72–0.98 dL/g) were prepared by the low temperature polycondensation of BCPX with various aromatic diamines in N,N‐dimethylacetamide (DMAc) solution containing pyridine (Py). All new polyamides were amorphous and readily soluble in various polar solvents such as DMAc, N,N‐dimethylformamide (DMF), N‐methyl‐2‐pyrrolidone (NMP) and Py. These polymers showed relatively high glass transition temperatures between 236 and 298°C, decomposition temperatures at 10% weight loss ranging from 490 to 535°C and 483 to 515°C in nitrogen and air, respectively, and char yields at 700°C in nitrogen higher than 50%. Transparent, flexible, and tough films of these polymers cast from DMAc solutions exhibited tensile strengths ranging from 82 to 106 MPa, elongations at break from 10% to 25%, and initial moduli from 2.0 to 2.8 GPa.     

Synthesis and characterization of new soluble cardo polyamides containing the tricyclo[5.2.1.02,6]decane group

A new cardo dicarboxylic acid, 8,8‐bis[4‐(4‐carboxyphenoxy)phenyl]tricyclo[5.2.1.0^2,6]decane (BCPTD), was synthesized from 4,4′‐(octahydro‐4,7‐methano‐5H‐inden‐5‐ylidene)bisphenol and p‐fluorobenzonitrile via aromatic nucleophilic substitution followed by hydrolysis. A series of new cardo polyamides was prepared by the direct polycondensation of BCPTD and various aromatic diamines in N‐methyl‐2‐pyrrolidinone (NMP) with triphenyl phosphite and pyridine as the condensing agents. Polymers were produced with moderate to high inherent viscosities of 0.65 to 1.08 dL g⁻¹. The polymers, except for polymer PA1 , exhibited number‐average molecular weights and weight‐average molecular weights in the range of 38,400 to 86,300 and 57,800 to 148,000, respectively. Nearly all of the polymers were readily soluble in polar solvents such as NMP, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide as well as in less polar solvents such as pyridine, γ‐butyrolactone, and tetrahydrofuran. All of the polymers were amorphous, and the polyamide films had a tensile‐strength range of 75 to 128 MPa and a tensile‐modulus range of 2.0 to 2.8 GPa. These polyamides had glass‐transition temperatures between 240 and 269°C and 10% weight‐loss temperatures in the range of 477 to 508°C and 471 to 518°C in nitrogen and air atmospheres, respectively. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 74–79, 2000     

Synthesis and characterization of new soluble aromatic polyamides based on 4‐(1‐adamantyl)‐1, 3‐bis(4‐aminophenoxy)benzene

A set of new aromatic polyamides were synthesized by the direct phosphorylation condensation of 4‐(1‐adamantyl)‐1,3‐bis‐(4‐aminophenoxy)benzene with various diacids. The polymers were produced with high yields and moderate to high inherent viscosities (0.43–1.03 dL/g), and the weight‐average molecular weights and number‐average molecular weights, determined by gel permeation chromatography, were in the range of 37,000–93,000 and 12,000–59,000, respectively. The polyamides were essentially amorphous and soluble in a variety of solvents such as N,N‐dimethylacetamide (DMAc), cyclohexanone, and tetrahydrofuran. They showed glass‐transition temperatures in the range of 240–300 °C (differential scanning calorimetry) and 10% weight‐loss temperatures over 450 °C, as revealed by thermogravimetric analysis in nitrogen. All the polymers gave strong films via casting from DMAc solutions, and these films exhibited good mechanical properties, with tensile strengths in the range of 77–92 MPa and tensile moduli between 1.5 and 2.5 GPa. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1014–1023, 2000     

Preparation and properties of aramid/layered silicate nanocomposites by solution intercalation technique

Polymer—clay nanocomposites were synthesized from aromatic polyamide and organoclay using the solution intercalation technique. Polyamide chains were produced through the reaction of 4,4′‐oxydianiline (ODA) and isophthaloyl chloride (IPC) in N, N′‐dimethyl acetamide, using stoichiometry yielding chains with carbonyl chloride end groups. The intercalation of sodium montmorillonite (Na‐MMT) was carried out using p‐phenylene diamine as a swelling agent through an ion exchange reaction. Different concentrations of organoclay were blended with the polyamide solution for complete dispersion of clay throughout the matrix. The resulting composite films were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), mechanical testing, thermogravimetry (TGA), differential scanning calorimetry (DSC) and water absorption measurements. The XRD pattern and morphology of the nanocomposites revealed the formation of exfoliated and intercalated clay platelets in the matrix. The film containing a small amount of clay was semitransparent and had a tensile strength of the order of 70 MPa (relative to the 52 MPa of the pure aramid). Thermal decomposition temperatures were in the range of 300–450°C and the weight of the samples remaining after heating to 900°C was found to be roughly proportional to the clay loading. DSC showed a systematic increase in the glass transition temperature with increase in clay content. Water absorption of the pristine aramid film was rather high (5.7%), which reduced upon loading of organoclay. Copyright © 2008 John Wiley & Sons, Ltd.     

Polyurethanes containing sulfur. I. New thermoplastic polyurethanes with benzophenone unit in their structure

New thermoplastic nonsegmented thiopolyurethanes were obtained from the low-melting aliphatic–aromatic thiodiols 4,4′-bis(2-hydroxyethylthiomethyl)benzophenone (BHEB), 4,4′-bis(3-hydroxypropylthiomethyl)benzophenone (BHPB), and 4,4′-bis(6-hydroxyhexylthiomethyl)benzenophenone(BHHB) as well as hexamethylene diisocyanate (HDI), both by melt and solution polymerization with dibutyltin dilaurate as the catalyst. The effect of various solvents on molecular-weight values was examined. The polymers with the highest reduced viscosities (0.63–0.88 dL/g) were obtained when the polymerization was carried out in a solution of tetrachloroethane, N,N-dimethylacetamide, and N,N-dimethylacetamide or N,N-dimethylformamide for BHEB-, BHPB-, and BHHB-derived polyurethanes, respectively. These polymers with a partially crystalline structure showed glass-transition temperatures (T_g) in the range of −1 to 39 °C, melting temperatures (T_m) in the range of 107 to 124 °C, and thermal stabilities up to 230 to 240 °C. The BHEB-derived polyurethane is a low-elasticity material with high tensile strength (ca. 50 MPa), whereas the BHPB- and BHHB-derived polyurethanes are more elastic, showing yield stress at approximately 16 MPa. We also obtained segmented polyurethanes by using BHHB, HDI, and 20 to 80 mol % poly(oxytetramethylene) glycol (PTMG) of M̄_n = 1000 as the soft segment. These are high-molecular thermoplastic elastomers that show a partially crystalline structure. Thermal properties were investigated by thermogravimetric analysis and differential scanning calorimetry. The increase in PTMG content decreases the definite T_g and increases the solubility of the polymers. These segmented polyurethanes exhibit the definite T_g (−67 to −62 °C) nearly independent of the hard-segment content up to approximately 50 wt %, indicating the existence of mainly phase-separated soft and hard segments. Shore A/D hardness and tensile properties were also determined. As the PTMG content increases, the hardness, modulus of elasticity, and tensile strength decrease, whereas elongation at break increases. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4140–4150, 1999     

Synthesis and properties of hyperbranched polyimides derived from novel triamine with prolonged chain segments

Novel pyridine‐containing hyperbranched polyimides (HBPIs) were synthesized by using a new triamine 2,4,6‐tris[3‐(4‐aminophenoxy)phenyl]pyridine with prolonged chain segments, ether linkage and meta‐linked units as a BB′₂‐like monomer, various commercial aromatic dianhydrides as A₂ monomers. Most of the obtained HBPIs were readily soluble in common organic solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidone, m‐Cresol, and so forth. Meanwhile, they also had good thermal stability with the glass transition temperatures (T_gs) all above 210 °C, the temperature at 10% weight loss of 537.1–574.4 °C in nitrogen atmosphere. Strong and flexible HBPI films were obtained, which had good mechanical properties with tensile strengths of 83.3–95.8 MPa, tensile modulus of 1.82–2.43 GPa and elongations at break of 4.84–6.98%. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2425–2437     

Synthesis and characterization of new organosoluble polyamides derived from bis[4‐(4‐carboxyphenoxy) phenyl]diphenylmethane

A new dicarboxylic acid containing a diphenylmethylene linkage, bis[4‐(4‐carboxyphenoxy)phenyl]diphenylmethane (BCAPD), was prepared from bis(4‐hydroxphenyl)diphenylmethane and p‐fluorobenzonitrile via an aromatic nucleophilic substitution reaction followed by hydrolysis. A series of novel polyamides were prepared by the direct polycondensation of BCAPD and various aromatic diamines. The polymers were produced with moderate to high inherent viscosities of 0.80–0.85 dL g^?1. Nearly all the polymers were readily soluble in polar solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide, in less polar solvents such as pyridine and cyclohexanone, and in tetrahydrofuran. All the polymers were amorphous, and the polyamide films had a tensile strength and a tensile modulus greater than 80 MPa and 2.0 GPa, respectively. These polyamides had glass‐transition temperatures between 249 and 274 °C, and their temperatures at a 10% weight loss were 477–538 and 483–540 °C in nitrogen and air atmospheres, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1156–1161, 2001     

Novel poly(fluorinated imide)s containing naphthalene pendant group: synthesis and characterization

A new fluorinated diamine monomer containing naphthalene pendant group, bis(4-amino-3,5-difluorophenyl)naphthylmethane (monomer 1), was synthesized from 1-naphthaldehyde and 2,6-difluoroaniline with trifluoromethanesulfonic acid at reflux. The novel poly(fluorinated imide)s (PFIs) were prepared via one-step polycondensation by monomer 1 and three aromatic dianhydrides including 4,4′-oxydiphthalic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, and 3,3′,4,4′-biphenyltetracarboxylic dianhydride in m-cresol, respectively. The obtained PFIs could be dissolved in a variety of organic solvents such as N-methyl-2-pyrrolidinone, N,N-dimetahylacetamide (DMAC), N,N-dimethylformamide, chloroform, and tetrahydrofuran at room temperature. The highest solubility of PFIs could even reach to 250 mg/mL in chloroform. The PFIs could be easily processed into flexible and tough films by casting onto glass from DMAC solution. The PFI films had a tensile strength, elongation at break, and tensile modulus in the range of 84–102 MPa, 8.7–12.8%, and 2.2–2.8 GPa, respectively. These polymers also showed excellent thermal stability with glass transition temperatures in the range of 326–352 °C, 10% weight loss temperatures in the range of 538–574 °C, and the weight residue more than 57% at 800 °C in nitrogen. Moreover, as for the optical properties, these PFIs exhibited a strong optical absorption in the ultraviolet region (290–370 nm) and photoluminescence in dilute chloroform solution or solid state.