Synthesis and characterization of polyamides derived from (4-(4-(2, 6-diphenylpyridin-4yl)phenoxy)phenyl)-3, 5-diaminobezamide

New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,¹H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N₂.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_max in the range of 470-550 nm.     

New poly(amide-imide)s syntheses. VII. Preparation and properties of poly(amide-imide)s derived from 1,5-bis(4-aminophenoxy) naphthalene,trimellitic anhydride,and various aromatic diamines

New bis(phenoxy)naphthalene-containing poly(amide-imide)s having an inherent viscosity in the range of 0.62–1.09 dL/g were prepared by the direct polycondensation of 1,5-bis(4-trimellitimidophenoxy) naphthalene ( I ) and various aromatic diamines using triphenyl phosphite and pyridine as condensing agents in N-methyl-2-pyrrolidone (NMP) in the presence of calcium chloride. The diimide-diacid (I) was prepared by the condensation of 1,5-bis(4-aminophenoxy) naphthalene and trimellitic anhydride. Most of the polymers were soluble in aprotic solvents such as NMP and N,N-dimethylacetamide (DMAc), and afforded transparent, flexible and tough films upon casting from DMAc solutions. Measurements of wide-angle X-ray diffraction revealed that those polymers containing p-phenylene or oxyphenylene groups were characterized as crystalline polymers. Tensile strength and initial moduli of the polymer films ranged from 61–86 MPa and 1.83–2.21 GPa, respectively. Glass transition temperatures of the polymers were in the range of 231–340°C. The melting points of the crystalline polymers ranged from 375–430°C. The 10% weight loss temperatures were above 512°C in nitrogen and 481°C in air. © 1993 John Wiley & Sons, Inc.     

New poly(amide-imide) syntheses. XII. Preparation and properties of poly(amide-imide)s based on the diimide-diacid condensed from 9,9-bis[4-(4-aminophenoxy)phenyl] fluorene and trimellitic anhydride

A dicarboxylic acid ( I ) was prepared from the condensation of 9,9-bis[4-(4-aminophenoxy) phenyl] fluorene and trimellitic anhydride. A new family of poly(amide-imide)s having inherent viscosities of 0.75-1.04 dL/g was prepared by the triphenyl phosphite activated polycondensation from the diimide-diacid I with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidone (NMP), pyridine, and calcium chloride. Most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All the soluble poly(amide-imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 262–325°C and the 10% weight loss temperatures were above 525°C in air. © 1994 John Wiley & Sons, Inc.     

Synthesis,Characterization, and Functionalization of Hyperbranched Poly(ether ether ketone)s with Phenoxypheyl Side Group

Novel fluoride‐teminated hyperbranched poly(ether ether ketone) with 4‐phenoxyphenyl side group (HPEEK‐F) was prepared from 2‐(4‐phenoxyphenyl)‐1,4‐diphenol (A₂) and 1,3,5‐tris[4‐(4‐flourobenzoyl) phenoxy]benzene (B₃). An end‐capping approach was used to synthesize tertiary amino‐terminated fluorescent (HPEEK‐DMA) and phenyl ethynyl‐terminated self‐crosslinking poly(ether ether ketone)s (HPEEK‐PEP). These three polymers have the same backbone structure and degree of branching (DB=0.67), and different terminal groups. The nature of the terminal group was shown as the influences of the glass transition temperature (T_g) and decomposition temperature (T_d) of polymers. The T_g of HPEEK‐F and HPEEK‐DMA are 30°C lower than HPEEK‐PEP, whereas the T_d of HPEEK‐F are 90°C and 50°C higher than HPEEK‐DMA and HPEEK‐PEP, respectively. The HPEEK‐DMA fluoresce blue‐green in solid and in solution. This kind of hyperbranched polymer contains a large amount of terminal chromophore groups which can easily lead to the formation of intramolecular excimers. The fluorescence signal was decreased with increasing acidity, furthermore, the two peaks at 466 nm and 507 nm indicated a blue shift occurred. After curing, the HPEEK‐PEP displayed a T_g at 235.5°C, which is 100°C higher than original polymers. Thermally cured samples show good anti‐chemical corrodibility in DMF, THF, DMAc and NMP solvents.     

Preparation and Properties of Novel Aromatic Polyamides from Diamines Containing 4,5-Imidazolediyl Structure

Novel aromatic polyamides were prepared from aromatic diamine containing 4,5-imidazolediyl unit, either by low temperature solution polycondensation or by direct polycondensation. Used diamines were 4,5-bis(4-aminophenyl)-2-phenylimidazole 1, 4,5-bis[4-(4-aminophenyl)]-2-(4-methylphenyl)imidazole 2 and 4,5-bis[4-(4-aminophenoxy)phenyl]-2-phenylimidazole 3. The obtained aromatic polyamides were produced with moderate to high inherent viscosity and soluble in polar aprotic solvents such as N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Thermogravimetric analysis showed those polymers were stable up to 422°C in nitrogen atmosphere. The glass transition temperature (T _g)s of the polymers derived from diamine 3 were in the range between 243 and 275°C, and these values were approximately 120–160°C lower than those analogue polyamide I series containing no phenoxy units. The properties of polyamide I series are also compared with those of analogue polymers that order of aromatic nuclei and amide linkage is reversible.     

New poly(amide-lmide)s syntheses. XV. Preparation and properties of poly(amide-imide)s derived from 9, 9-bis[4-(4-aminophenoxy) phenyl]fluorene and various bis(trimellitimide)s

Fifteen bis(phenoxy) fluorene-containing poly(amide-imide)s III were synthesized by the direct polycondensation of 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene (BAPPF) with var-ious aromatic bis(trimellitimide)s II in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. Poly(amide-imide)s III having inherent vis-cosities up to 1.45 dL/g were obtained in quantitative yields. Most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All the soluble poly(amide-imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 263–315°C and the 10% weight loss temperatures were above 510°C in nitrogen. Some properties of poly(amide-imide)s III were compared with those of the corresponding isomeric poly(amide-imide)s III ′ prepared from 9,9-[4-(4-trimellitimidophenoxy)phenyl]fluorene and various aromatic diamines. © 1995 John Wiley & Sons, Inc.     

Preparation and properties of imide‐containing elastic polymers from elastic polyureas and pyromellitic dianhydride

A new approach to obtain imide‐containing elastic polymers (IEPs) via elastic and high‐molecular‐weight polyureas, which were prepared from α‐(4‐aminobenzoyl)‐ω‐[(4‐aminobenzoyl)oxy]‐poly(oxytetramethylene) and the conventional diisocyanates such as tolylene‐2,4‐diisocyanate(2,4‐TDI), tolylene‐2,6‐diisocyanate(2,6‐TDI), and 4,4′‐diphenylmethanediisocyanate (MDI), was investigated. IEP solutions were prepared in high yield by the reaction of the polyureas with pyromellitic dianhydride in N‐methyl‐2‐pyrrolidone (NMP) at 165°C for 3.7–5.2 h. IEPs were obtained by the thermal treatment at 200°C for 4 h in vacuo after NMP was evaporated from the resulting IEP solutions. We assumed a mechanism of the reaction via N‐acylurea from the identification of imide linkage and amid acid group in IEP solutions. NMR and FTIR analyses confirmed that IEPs were segmented polymers composed of imide hard segment and poly(tetramethylene oxide) (PTMO) soft segment. The dynamic mechanical and thermal analyses indicated that the IEPs prepared from 2,6‐TDI and MDI showed a glass‐transition temperature (T_g ) at about −60°C, corresponding to T_g of PTMO segment, and suggested that microphase‐separation between the imide segment and the PTMO segment occured in them. TGA studies indicated the 10% weight‐loss temperatures (T₁₀) under air for IEPs were in the temperature range of 343–374°C. IEPs prepared from 2,6‐TDI and MDI showed excellent tensile properties and good solvent resistance. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 715–723, 2000     

New poly(amide-imide)s syntheses. XVII. Preparation and properties of poly(amide-imide)s derived from 3,3-Bis[4-(4-aminophenoxy)phenyl]phthalimidine and various bis(trimellitimide)s

A series of novel bis(phenoxy)phthalimidine-containing poly(amide-imide)s III were synthesized by the direct polycondensation of 3,3-bis[4-(4-aminophenoxy)phenyl]phthalimidine (BAPP) with various aromatic bis(trimellitimide)s in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. Poly(amide-imide)s III , having inherent viscosities up to 1.36 dL/g, were obtained in quantitative yields. All resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All the soluble poly(amide-imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 267–322°C and the 10% weight loss temperatures were above 490°C in nitrogen. Some properties of poly(amide-imide)s III were compared with those of the corresponding isomeric poly(amide-imide)s III′ prepared from 3,3-[4-(4-trimellitimidophenoxy)phenyl]-phthalimidine and various aromatic diamines. © 1996 John Wiley & Sons, Inc.     

Polypyrazolinones from aromatic di(propynoic ester)s and aromatic dihydrazines

Novel polypyrazolinones with inherent viscosities ranging from 0.12 to 0.44 dL/g were prepared by the Michael-type nucleophilic addition-cyclization of various dihydrazines with 3,3′-(1,3- or 1,4-phenylene)bis(ethyl propynoate) (1,3- or 1,4-PEP) and 3,3′-(1,4-phenylene)bis(phenyl propynoate) (1,4-PPhP) in N-methylpyrrolidone (NMP) solution at 25–110°C. The polymers exhibited moderate thermal stability with initial weight loss in air about 200°C and in nitrogen about 300°C (TGA). No apparent T_g′s were observed by DSC analysis. The synthesis and characterization of the polypyrazolinones is discussed.     

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     

Organosoluble and thermally stable polyimides derived from a new diamine containing bulky-flexible triaryl pyridine pendent group

A novel kind of aromatic diamine,N-(4-(4-(2,6-diphenyl pyridine-4-yl)phenoxy)phenyl)-3,5-diaminobezamide (DPDAB),was synthesized via aromatic nucleophilic substitution of 3,5-dinitrobenzoylchloride with 4-(4-(2,6- diphenylpyridine-4-yl)phenoxy)aniline(DPPA),followed by palladium-catalyzed hydrazine reduction.This monomer was used to prepare polyimides(PIs)based on reaction with several commerically avaiable tetracarboxylic dianhydrides such as pyromellatic dianhydride(PMDA),benzophenone tetracarboxylic acide dianhydride(BTDA)and bicycle[2.2.2]oct-7-enc- 2,3,5,6-tetracarboxylic dianhydride(BCDA).These PIs had inherent viscosity in the range of 0.34-0.76 dL/g and showed good solubility in various aprotic polar solvents.The glass-transition tempratures(T_gs)of the PIs were in the range of 184-302℃,and showed high thermal stability with 10%weight loss in the temperature range of 360-500℃under nitrogen atmosphere.     

Synthesis and polymerization of new self‐polymerizable quinoxaline monomers

Extended self‐polymerizable poly(phenylquinoxaline) monomer mixtures {i.e.,2‐[4‐(4‐hydroxyphenoxy)phenyl]‐3‐phenyl‐6‐chloroquinoxaline and 3‐[4‐(4‐hydroxy phenoxy)phenyl]‐2‐phenyl‐6‐chloroquinoxaline, 2‐[4‐(4‐hydroxyphenoxy)phenyl]‐3‐phenyl‐6‐fluoroquinoxaline and 3‐[4‐(4‐hydroxyphenoxy)phenyl]‐2‐phenyl‐6‐fluoroquinoxaline, and 2‐(4‐fluorophenyl)‐3‐phenyl‐6‐(4‐hydroxyphenoxy)quinoxaline and 3‐(4‐fluorophenyl)‐2‐phenyl‐6‐(4‐hydroxyphenoxy)quinoxaline} more flexible and nucleophilic than a previously reported monomer mixture [i.e., 3‐(4‐hydroxyphenyl)‐2‐phenyl‐6‐fluoroquinoxaline and 2‐(4‐hydroxyphenyl)‐3‐phenyl‐6‐fluoroquinoxaline] were synthesized. The monomer mixtures were then polymerized into high‐molecular‐weight polymers. A sample was obtained, through a chlorine displacement reaction, that was a semicrystalline polymer with an intrinsic viscosity of 1.11 dL/g in m‐cresol at 30 ± 0.1 °C and two melting temperatures at 339 and 377 °C in the first differential scanning calorimetry scan. There was a melting temperature at 328 °C without a detectable glass‐transition temperature (T_g) when the sample was subjected to a second differential scanning calorimetry scan. The samples from fluorine displacement reactions were completely amorphous polymers. They had intrinsic viscosities of 0.53–0.90 dL/g in m‐cresol at 30 ± 0.1 °C and T_g's of 220–224 °C. The polymer samples from fluorine displacement reactions were evaluated with gel permeation chromatography and matrix‐assisted laser desorption/ionization time‐of‐flight analyses, which monitored the existence of certain amounts of cyclic oligomers. The thin films of the polymers had room‐temperature tensile strengths of 97–113 MPa, room‐temperature Young's moduli of 2.30–2.35 GPa, and room‐temperature elongations at break of 40–150%. The melt viscosity decreased from 10⁷ to less than 10⁴ Pa s at 310 °C as the frequency was increased from 10^?2 to 10² rad/s. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 78–91, 2005     

New poly(amide-imide)s syntheses. VIII. Preparation and properties of poly (amide-imide)s derived from 2,3-bis(4-aminophenoxy)naphthalene,trimellitic anhydride,and various aromatic diamines

The new polymer-forming diimide-diacid, 2,3-bis(4-trimellitimidophenoxy) naphthalene (I), was readily obtained by the condensation reaction of 2,3-bis (4-aminophenoxy) naphthalene with trimellitic anhydride. A series of novel aromatic poly (amide-imide)s were prepared by the direct polycondensation of diimide-diacid I with various aromatic diamines using triphenyl phosphite in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved calcium chloride. The resultant polymers have inherent viscosities in the range of 0.65–1.02 dL/g at 30°C in N, N-dimethylacetamide. These polymers were readily soluble in various organic solvents and could be cast into transparent, tough, and flexible films. Their casting films showed tensile strength at break up to 86 MPa, elongation to break of 5–9%, and initial moduli up to 2.35 GPa. The wide-angle X-ray diffraction revealed that those polymers containing p-phenylene or p-oxyphenylene group are partially crystalline, and the other polymers are evidenced as amorphous patterns. These polymers show a glass transition in the range of 213–290°C in their differential scanning calorimetry (DSC) traces. The thermal stability of the polymers was evaluated by thermogravimetry analysis, which showed the 10% weight-loss temperatures in the range of 508–565°C in nitrogen and 480–529°C in air atmosphere. © 1994 John Wiley & Sons, Inc.     

Synthesis and properties of poly(amide-imide)s based on the diimide-diacid condensed from 2,2′- bis(4-aminophenoxy)biphenyl and trimellitic anhydride

A new dicarboxylic acid having a kinked structure was synthesized from the condensation of 2,2′-bis(4-aminophenoxy)biphenyl and trimellitic anhydride. A series of biphenyl-2,2′-diyl-containing aromatic poly(amide-imide)s having inherent viscosities of 0.23–0.94 dL/g was prepared by the triphenyl phosphite activated polycondensation from the diimide-diacid II with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidone (NMP), pyridine, and calcium chloride. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents including NMP and N,N-dimethylacetamide (DMAc). Transparent, flexible, and tough films of these polymers could be cast from DMAc or NMP solutions. The glass transition temperatures of these polymers were in the range of 227–261°C and the 10% weight loss temperatures were above 520°C in nitrogen. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1169–1177, 1998     

Synthesis and characterization of new aromatic poly(amide-imide)s derived from bis(3-trimellitimidophenyl) phenyl phosphine oxide and various aromatic diamines

New aromatic poly(amide-imide)s with high inherent viscosities were prepared by direct polycondensation reaction of diimide-diacid (I) and aromatic diamines using triphenyl phosphite in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved CaCl₂. The bis(3-trimellitimidophenyl) phenyl phosphine oxide (I) was readily obtained by the condensation reaction of bis(3-aminophenyl) phenyl phosphine oxide (BAPPO) with trimellitic anhydride. The resulting poly(amide-imide)s showed high thermostability. Their decomposition temperatures at 10% weight loss in nitrogen atmosphere were above 532 °C and the anaerobic char yield at 800 °C ranged from 56% to 74%. Almost all the poly(amide-imide)s showed high glass transition temperature above 233 °C by differential scanning calorimetry (DSC) measurements. These polymers were readily soluble in various organic solvents and by their casting into transparent, tough and flexible films can be easily achieved.     

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     

New poly(amide–imide) syntheses. XXI. Synthesis and properties of aromatic poly(amide–imide)s based on 2,6-bis(4-trimellitimidophenoxy)naphthalene and aromatic diamines

A novel polymer-forming diimide–diacid, 2,6-bis(4-trimellitimidophenoxy)naphthalene, was prepared by the condensation reaction of 2,6-bis(4-aminophenoxy)naphthalene with trimellitic anhydride (TMA). A series of novel aromatic poly(amide–imide)s containing 2,6-bis(phenoxy)naphthalene units were prepared by the direct polycondensation of the diimide–diacid with various aromatic diamines using triphenyl phosphite (TPP) in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved calcium chloride. Thirteen of the obtained polymers had inherent viscosities above 1.01 dL/g and up to 2.30 dL/g. Most of polymers were soluble in polar solvents such as DMAc and could be cast from their DMAc solutions into transparent, flexible, and tough films. These films had tensile strengths of 79–117 MPa, elongation-at-break of 7–61%, and initial moduli of 2.2–3.0 GPa. The wide-angle X-ray diffraction revealed that some polymers are partially crystalline. The glass transition temperatures of some polymers could be determined with the help of differential scanning calorimetry (DSC) traces, which were recorded in the range 232–300°C. All the poly(amide–imide)s exhibited no appreciable decomposition below 450°C, and their 10% weight loss temperatures were recorded in the range 511–577°C in nitrogen and 497–601°C in air. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 919–927, 1998     

New poly(amide-imide)s syntheses. I. Soluble high-temperature poly(amide-imide)s derived from 2,5-bis(4-trimellitimidophenyl)-3,4-diphenylthiophene and various aromatic diamines

Novel aromatic poly(amide-imide)s with high inherent viscosities were prepared by direct polycondensation reaction of 2,5-bis(4-trimellitimidophenyl)-3,4-diphenylthiophene ( IV ) and aromatic diamines using triphenyl phosphite in the N-methyl–2-pyrrolidone (NMP)/pyridine solution containing dissolved CaCl₂. The diimide-diacid IV was readily obtained by the condensation reaction of 2,5-bis(4-aminophenyl)-3,4-diphenylthiophene ( III ₁) with trimellitic anhydride. The obtained poly(amide-imide)s showed high thermostability. Their decomposition temperatures at 10% weight loss in nitrogen atmospheres were above 550°C and the anaerobic char yield at 800°C ranged from 48 to 68%. Almost all the poly(amide-imide)s showed high glass transition temperatures above 300°C by differential scanning calorimetry (DSC) measurements. These polymers were readily soluble in various organic solvents and could be cast into transparent, tough, and flexible films. Their casting films showed obvious yield points in the stress-strain curves and had strength at break up to 74.2 MPa, elongation to break up to 70.1%, and initial modulus up to 4.56 GPa. The factors affecting the reaction of diimide-diacid IV and 4,4′-oxydianiline in view of monomer concentration, reaction temperature, and amount of CaCl₂ were also investigated. © 1992 John Wiley & Sons, Inc.     

Synthesis and properties of aromatic polyamides containing the cyclohexane structure

1,1-Bis[4-(4-carboxyphenoxy)phenyl]cyclohexane (III) and 1,1-bis[4-(4-aminophenoxy)phenyl]cyclohexane (V) were prepared in two main steps starting from the aromatic nucleophilic substitution of p-fluorobenzonitrile and p-chloronitrobenzene, respectively, with 1,1-bis(4-hydroxyphenyl)cyclohexane in the presence of potassium carbonate in N,N-dimethylformamide (DMF). Using triphenyl phosphite and pyridine as condensing agents, two series of polyamides with cyclohexylidene cardo groups were directly polycondensated from dicarboxylic acid III with various aromatic diamines or from diamine V with various aromatic dicarboxylic acids in an N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride. The polyamides exhibited inherent viscosities in the range of 0.45 to 1.78 dL/g. Almost all of the polymers were readily soluble in polar aprotic solvents such as NMP and N,N-dimethylacetamide (DMAc) and could afford transparent, flexible, and tough films by solution casting. The glass transition temperatures (T_g) of these aromatic polyamides were in the range of 180–243°C by DSC, and the 10% weight loss temperatures in nitrogen and air were all above 450°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3575–3583, 1999     

Synthesis and characterization of fluorinated poly(aryl ether ketone)s containing 1,4-naphthalene moieties

The new monomer 2,2-bis[4-(4-{4-fluorobenzoyl}-1-naphthoxy)phenyl]hexafluoropropane ( 2 ) was synthesized in a two-step reaction sequence. 2,2-his[4-(1-naphthoxy)phenyl]-hexafluoropropane ( 1 ) was prepared using the Ullmann ether synthesis reaction of 4,4-(hex-afluoroisopropylidiene)diphenol with 1-bromonaphthalene. Friedel-Crafts acylation of 1 with 4-fluorobenzoyl chloride in methylene chloride containing dimethylsulfone selectively afforded 2 in 82% yield. The polycondensation of 2 with various bisphenols in DMAc in the presence of an excess of potassium carbonate as a condensation reagent was carried out at 165°C to quantitatively afford the corresponding fluorinated poly(aryl ether ketone)s containing 1,4-naphthalene moieties. Thermal analysis of the polymers showed them to have T_gs ranging from 194 to 230°C and to be thermally stable in air up with initial weight losses at about 500°C. In addition, these novel polymers exhibited excellent solubility in organic solvents including NMP, DMAc, and chloroform. © 1997 John Wiley & Sons, Inc.