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     

Fabrication and characterization of soluble,high thermal,and hydrophobic polyimides based on 4‐(3,5‐dimethoxyphenyl)‐2,6‐bis(4‐aminophenyl)pyridine

A novel aromatic diamine monomer, 4‐(3,5‐dimethoxyphenyl)‐2,6‐bis(4‐aminophenyl)pyridine (DPAP) was successfully synthesized by 4′‐nitroacetophenone and 3,5‐dimethoxybenzaldehyde as raw material. The structure of DPAP was confirmed by Fourier transform infrared, nuclear magnetic resonance, and mass analysis. A series of polyimides (PIs) were obtained by polycondensation with various dianhydrides via the conventional two‐step method. These PIs showed good solubility in organic solvents. They also presented high thermal stability, the glass transition temperatures (T_g) of polymers were in the range of 325–388 °C, and the temperature at 10% weight loss was in the range of 531–572 °C. Furthermore, these polymers also exhibited outstanding hydrophobicity with the contact angles in the range of 89.1°–93.5°. Moreover, the results of wide‐angle X‐ray diffraction (WAXD) confirmed these polymers showed amorphous structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45827.     

Synthesis and characterization of Schiff‐base‐containing polyimides

Benzyl bisthiosemicarbazone and its complexes with nickel (NiLH₄) and copper (CuLH₄) were used as diamine monomers for the synthesis of new Schiff‐base polyimides. The solution polycondensation of these monomers with the aromatic dianhydrides afforded metal‐containing Schiff‐base polyimides with inherent viscosities of 0.98–1.33 dL/g (measured in N‐methyl‐2‐pyrrolidone at 25°C). The polyimides were generally soluble in a wide range of solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, tetrahydrofuran, dimethyl sulfoxide, tetrachloroethane, hexamethylene phosphoramide, N‐methyl‐2‐pyrrolidone, ethyl acetate, and pyridine at room temperature. The initial degradation temperatures of the resultant polyimides fell in the range of 220–350°C in nitrogen with char yields ranging from 36 to 64% at 700°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of new optically active poly(amide‐imide‐urethane) thermoplastic elastomers,derived from 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L‐leucine‐p‐aminobenzoic acid) and PEG‐MDI

A new class of optically active poly(amide‐imide‐urethane) was synthesized via two‐step reactions. In the first step, 4,4′‐methylene‐bis(4‐phenylisocyanate) (MDI) reacts with several poly(ethylene glycols) (PEGs) such as PEG‐400, PEG‐600, PEG‐2000, PEG‐4000, and PEG‐6000 to produce the soft segment parts. On the other hand, 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine‐p‐amidobenzoic acid) (2) was prepared from the reaction of 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine) diacid chloride with p‐aminobenzoic acid to produce hard segment part. The chain extension of the above soft segment with the amide‐imide 2 is the second step to give a homologue series of poly(amide‐imide‐urethanes). The resulting polymers with moderate inherent viscosity of 0.29–1.38 dL/g are optically active and thermally stable. All of the above polymers were fully characterized by IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of this new optically active poly(amide‐imide‐urethanes) are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2288–2294, 2004     

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     

Synthesis and characterization of organosoluble polyfluorinated polyimides derived from 3,3′,5,5′‐tetrafluoro‐4,4′‐diaminodiphenylmethane and various aromatic dianhydrides

A polyfluorinated aromatic diamine, 3,3′, 5,5′‐tetrafluoro‐4,4′‐diaminodiphenylmethane (TFDAM), was synthesized and characterized. A series of polyimides, PI‐1–PI‐4, were prepared by reacting the diamine with four aromatic dianhydrides via a one‐step high‐temperature polycondensation procedure. The obtained polyimide resin had moderate inherent viscosity (0.56–0.68 dL/g) and excellent solubility in common organic solvents. The polyimide films exhibited good thermal stability, with an initial thermal decomposition temperature of 555°C–621°C, a 10% weight loss temperature of 560°C–636°C, and a glass‐transition temperature of 280°C–326°C. Flexible and tough polyimide films showed good tensile properties, with tensile strength of 121–138 MPa, elongation at break of 9%–12%, and tensile modulus of 2.2–2.9 GPa. The polyimide films were good dielectric materials, and surface and volume resistance were on the order of a magnitude of 10¹⁴ and 10¹⁵ Ω cm, respectively. The dielectric constant of the films was below 3.0 at 1 MHz. The polyfluorinated films showed good transparency in the visible‐light region, with a cutoff wavelength as low as 302 nm and transmittance higher than 70% at 450 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1442–1449, 2007     

Synthesis and characterization of melt‐processable polyimides derived from 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene

A series of molecular‐weight‐controlled imide resins end‐capped with phenylethynyl groups were prepared through the polycondensation of a mixture of 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene and 1,3‐bis(4‐aminophenoxy)benzene with 4,4′‐oxydiphthalic anhydride in the presence of 4‐phenylethynylphthalic anhydride as an end‐capping agent. The effects of the resin chemical structures and molecular weights on their melt processability and thermal properties were systematically investigated. The experimental results demonstrated that the molecular‐weight‐controlled imide resins exhibited not only meltability and melt stability but also low melt viscosity and high fluidability at temperatures lower than 280°C. The molecular‐weight‐controlled imide resins could be thermally cured at 371°C to yield thermoset polyimides by polymer chain extension and crosslinking. The neat thermoset polyimides showed excellent thermal stability, with an initial thermal decomposition temperature of more than 500°C and high glass‐transition temperatures greater than 290°C, and good mechanical properties, with flexural strengths in the range of 140.1–163.6 MPa, flexural moduli of 3.0–3.6 GPa, tensile strengths of 60.7–93.8 MPa, and elongations at break as high as 14.7%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

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     

Synthesis and characterization of organosoluble and transparent polyimides derived from trans‐1,2‐bis(3,4‐dicarboxyphenoxy)cyclohexane dianhydride

A novel dianhydride, trans‐1,2‐bis(3,4‐dicarboxyphenoxy)cyclohexane dianhydride (1,2‐CHDPA), was prepared through aromatic nucleophilic substitution reaction of 4‐nitrophthalonitrile with trans‐cyclohexane‐1,2‐diol followed by hydrolysis and dehydration. A series of polyimides (PIs) were synthesized from one‐step polycondensation of 1,2‐CHDPA with several aromatic diamines, such as 2,2′‐bis(trifluoromethyl)biphenyl‐4,4′‐diamine (TFDB), bis(4‐amino‐2‐trifluoromethylphenyl)ether (TFODA), 4,4′‐diaminodiphenyl ether (ODA), 1,4‐bis(4‐aminophenoxy)benzene (TPEQ), 4,4′‐(1,3‐phenylenedioxy)dianiline (TPER), 2,2′‐bis[4‐(3‐aminodiphenoxy)phenyl]sulfone (m‐BAPS), and 2,2′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]sulfone (6F‐BAPS). The glass transition temperatures (T_gs) of the polymers were higher than 198°C, and the 5% weight loss temperatures (T_d5%s) were in the range of 424–445°C in nitrogen and 415–430°C in air, respectively. All the PIs were endowed with high solubility in common organic solvents and could be cast into tough and flexible films, which exhibited good mechanical properties with tensile strengths of 76–105 MPa, elongations at break of 4.7–7.6%, and tensile moduli of 1.9–2.6 GPa. In particular, the PI films showed excellent optical transparency in the visible region with the cut‐off wavelengths of 369–375 nm owing to the introduction of trans‐1,2‐cyclohexane moiety into the main chain. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42317.     

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 characterization of novel polyimides derived from 2‐amino‐5‐(4‐aminophenyl)‐thiazole

A new kind of aromatic unsymmetrical diamine monomer containing thiazole ring, 2‐amino‐5‐(4‐aminophenyl)‐thiazole (AAPT), was synthesized. A series of novel polyimides were prepared by polycondensation of AAPT with various aromatic dianhydrides by one‐step polyimidation process. The synthesized polyimides had inherent viscosity values of 0.36–0.69 dL/g and were easily dissolved in highly dipolar solvents. Meanwhile, strong and flexible polyimide films were obtained, which have good thermal and thermo‐oxidative stability with the glass transition temperatures (T_g) of 276.7–346.1°C, the temperature at 5% weight loss of 451–492°C in nitrogen and 422–440°C in air, as well as have outstanding mechanical properties with the tensile strengths of 94–122 MPa, elongations at breakage of 5–18%. These films also had dielectric constants of 3.12–3.38 at 10 MHz. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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     

Polyimides derived from 1,4‐bis [3‐oxy‐(N‐aminophthalimide)] benzene

A novel diamine, 1,4‐bis [3‐oxy‐(N‐aminophthalimide)] benzene (BOAPIB), was synthesized from 1,4‐bis [3‐oxy‐(N‐phenylphthalimide)] benzene and hydrazine. Its structure was determined via IR, ¹H NMR, and elemental analysis. A series of five‐member ring, hydrazine‐based polyimides were prepared from this diamine and various aromatic dianhydrides via one‐step polycondensation in p‐chlorophenol. The inherent viscosities of these polyimides were in the range of 0.17–0.61 dL/g. These polymers were soluble in polar aprotic solvents and phenols at room temperature. Thermogravimetric analysis (TGA) showed that the 5% weight‐loss temperatures of the polyimides were near 450°C in air and 500°C in nitrogen. Dynamic mechanical thermal analysis (DMTA) indicated that the glass‐transition temperatures (T_gs) of these polymers were in the range of 265–360°C. The wide‐angle X‐ray diffraction showed that all the polyimides were amorphous. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and properties of polyimides from isomeric bis(dicarboxylphenylthio)diphenyl sulfone dianhydrides

4,4′-Bis(3,4-dicarboxyphenylthio)diphenyl sulfone dianhydride(4,4′-PTPSDA) and 4,4′-bis(2,3-dicarboxyphenylthio)diphenyl sulfone dianhydride(3,3′-PTPSDA) were synthesized from chlorophthalic anhydrides and bis(4-mercaptophenyl)sulfone. Their structures were determined via IR spectra, ¹H NMR and elemental analysis. A series of polyimides were prepared from isomeric PTPSDAs and aromatic diamines in 1-methyl-2-pyrrolidinone (NMP) via the conventional two-step method. Polyimides based on 4,4′-PTPSDA and 3,3′-PTPSDA have good solubility in polar aprotic solvents and phenols. The 5% weight-loss temperatures of isomeric polyimides were near 500 °C in N₂. DMTA and DSC analyses indicated that the glass-transition temperatures of polyimides from 3,3′-PTPSDA are higher than those of polyimides from 4,4′-PTPSDA. The wide-angle X-ray diffraction showed that all polyimides are amorphous. The polyimides from 3,3′-PTPSDA showed higher permeability but lower permselectivity compared with those from 4,4′-PTPSDA.     

Synthesis and characterization of organo‐soluble fluorinated polyimides

A novel fluorinated diamine monomer with a keto group, 4‐[4‐amino‐2‐trifluoromethyl phenoxy]‐4′‐[4‐aminophenoxy]benzophenone (ATAB) was prepared by reacting dihydroxybenzophenone with 4‐chloronitrobenzene and 2‐chloro‐5‐nitrotrifluoromethylbenzene in the presence of potassium carbonate followed by catalytic reduction with palladized carbon (10%). Fluorinated polyimides IVa–e were synthesized from the diamine mentioned above via a two‐step method (thermal and chemical imidization). Polyimides IVa–e have inherent viscosities in the range 0.65–1.06 dL g^?1 (thermal imidization) and 0.82–1.56 dL g^?1 (chemical imidization). The polyimides prepared by chemical imidization exhibit excellent solubility. Polyimide films exhibit tensile strength, elongation and tensile modulus in the ranges 96–106 MPa, 9–13% and 1.1–1.7 GPa, respectively. The T₁₀ values of the polyimides are in the range 540–598 °C in nitrogen and 545–586 °C in air, with more than 50–60% char yield. They have T_g values between 244 and 285 °C. The prepared polyimides show cut‐off wavelengths in the range 365–412 nm and transmittance at 450 nm in the range 80.9–94.2%. The dielectric constants of the polyimide films are in the range 3.10–3.77 at 1 kHz and 3.04–3.66 at 10 kHz, with moisture absorption of 0.14–0.40%. Copyright © 2006 Society of Chemical Industry     

Synthesis and characterization of some aromatic polyimides

The diamine 2‐methyl‐1,3‐bis(4‐aminophenyloxy)benzene was prepared via a nucleophilic substitution reaction and was characterized with Fourier transform infrared, elemental analysis, and ¹H‐ and ¹³C‐NMR spectroscopy. The prepared diamine was also characterized with single‐crystal analysis. The geometric parameters of C₁₉H₁₈N₂O₂ were in the usual ranges. The dihedral angles between the central phenyl ring and the two terminal aromatic rings were 88.9 and 91.6°. The crystal structure was stabilized by N? H···N hydrogen bonds. The diamine was then polymerized with 3,3′,4,4′‐benzophenone tetracarboxylic acid dianhydride, 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, 3,4,9,10‐perylenetetracarboxylic acid dianhydride, and pyromellitic dianhydride by either a one‐step solution polymerization reaction or a two‐step procedure. These polymers had inherent viscosities ranging from 0.61 to 0.85 dL/gm. Some of the polymers were soluble in most common organic solvents even at room temperature, and some were soluble on heating. The degradation temperatures of the resultant polymers fell in the range of 260–500°C in nitrogen (with only 10% weight loss). The specific heat capacity at 200°C ranged from 1.0 to 2.21 J g^?1 K^?1. The temperatures at which the maximum degradation of the polymer occurred ranged from 510 to 610°C. The glass‐transition temperatures of the polyimides ranged from 182 to 191°C. The activation energy and enthalpy of the polyimides ranged from 44.44 to 73.91 kJ/mol and from 42.58 to 72.08 kJ/mol K, respectively. The moisture absorption was found in the range of 0.23–0.71%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Soluble and light‐colored polyimides from 2,3,2′,3′‐oxydiphthalic anhydride and aromatic diamines

A series of polyimides were prepared from 2,3,2′,3′‐oxydiphthalic anhydride (3,3′‐ODPA) with various aromatic diamines via three different synthetic procedures. The one‐step and two‐step methods with the thermal imidization of poly(amic acids) (PAAs) yielded polyimides with a relatively low inherent viscosity; these produced brittle films. The polyimides prepared by the two‐step method via the chemical imidization of PAA precursors exhibited a higher inherent viscosity and afforded tough and creaseable films. All the 3,3′‐ODPA based polyimides had a significantly higher solubility than the corresponding polyimides from 3,4,3′,4′‐oxydiphthalic anhydride. The films cast from 3,3′‐ODPA polyimides also showed high optical transparencies and less color, with an ultraviolet–visible absorption edge of 370–397 nm and low yellowness index values of 11.3–29.8. These polyimides exhibited glass‐transition temperatures in the range 211–289°C and showed no significant decomposition below 500°C under nitrogen or air atmospheres. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1352–1360, 2005     

Synthesis and properties of novel organosoluble bismaleimides and polyaspartimides containing bis(4‐maleimido‐3, 5‐dimethyl phenyl) halo phenyl methane

A series of bismaleimides was synthesized from bis(4‐amino‐3, 5‐dimethylphenyl) (X) phenyl methane (X = 3′chloro, 3′‐bromo, 3′‐benzyloxy, 4′‐chloro, 4′‐fluoro) and maleic anhydride. The bismaleimides were subsequently polymerized with various diamines by Michael addition to yield novel polyaspartimides. All the polymers exhibited good solubility in organic solvents and the inherent viscosity of the polymers were in the range of 0.40–0.56 dL/g, which is good enough to fabricate composites and films. The temperature at which 10% weight loss occurred was in the range of 390–441°C. The polymers had high glass transition temperature in the range of 205–275°C and left about 31.95–84.20% char yield at 800°C indicating that they have good self‐extinguishing property. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermal behavior and cured products of bis(4‐maleimidodiphenyl)methane,bis(isomaleimidodiphenyl)methane and 4,4′‐diaminodiphenyl methane mixtures

The thermal behavior of mixtures of bis(4‐maleimidophenyl) (A) with bis(4‐isomaleimidophenyl)methane (C) and their mixture with 4,4′‐diaminodiphenyl methane (D) were investigated by differential scanning calorimetry. The study of the binary system A/C in different proportions led us to determine an eutectic mixture at a molar fraction of C in the range of 0.7–0.9. The ternary ACD mixtures showed themselves able to participate in three principal reactions: polyaddition, ring‐opening addition, and homopolymerization. In each mixture studied the addition of diamine changed the melting point and maximum polymerization temperatures in the sense of a general decrease. The properties of the networks were studied by thermal analysis and through evaluation of water absorption. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3547–3556, 2003     

Synthesis,characterization, and thermal degradation of oligo‐2‐(morpholinoiminomethyl)phenol and its Pb(II) complex compound

The oxidative polycondensation reaction conditions of 2‐(morpholinoiminomethyl)phenol were studied with H₂O₂, air O₂, and sodium hypochloride (NaOCl) oxidants in an aqueous alkaline medium between 40 and 90°C. The structure of oligo‐2‐(morpholinoiminomethyl)phenol was characterized with ¹H‐ and ¹³C‐NMR, Fourier transform infrared, ultraviolet–visible, size exclusion chromatography, and elemental analysis techniques. Under the optimum reaction conditions, the yield of oligo‐2‐(morpholinoiminomethyl)phenol was 28% for the H₂O₂ oxidant, 12% for the air O₂ oxidant, and 58% for the NaOCl oxidant. According to the size exclusion chromatography analysis, the number‐average molecular weight, weight‐average molecular weight, and polydispersity index of oligo‐2‐(morpholinoiminomethyl)phenol were 2420 g/mol, 2740 g/mol, and 1.187 with H₂O₂, 1425 g/mol, 2060 g/mol, and 1.446 with air O₂, and 1309 g/mol, 1401 g/mol, and 1.070 with NaOCl, respectively. Thermogravimetry/dynamic thermal analysis showed that the oligo‐2‐(morpholinoiminomethyl)phenol–lead complex compound was more stable than 2‐(morpholinoiminomethyl)phenol and oligo‐2‐(morpholinoiminomethyl)phenol against thermal degradation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3795–3804, 2006