Synthesis,characterization, thermal stability,conductivity, and band gap of a new aromatic polyether containing an azomethine as a side

In this study, the oxidative polycondensation reaction conditions of 4‐[(4‐methylphenyl)iminomethyl]phenol (4‐MPIMP) were studied by using oxidants such as air O₂, H₂O₂, and NaOCl in an aqueous alkaline medium between 50 and 90°C. The structures of the synthesized monomer and polymer were confirmed by FTIR, UV–vis, ¹H–¹³C‐NMR, and elemental analysis. The characterization was made by TGA‐DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yield of poly‐4‐[(4‐methylphenyl)iminomethyl]phenol (P‐4‐MPIMP) was found to be 28% for air O₂ oxidant, 42% for H₂O₂ oxidant, and 62% for NaOCl oxidant. According to the SEC analysis, the number–average molecular weight (M_n), weight–average molecular weight (M_w), and polydispersity index values of P‐4‐MPIMP were found to be 4400 g mol^?1, 5100 g mol^?1, and 1.159, using H₂O₂, and 4650 g mol^?1, 5200 g mol^?1, and 1.118, using air O₂, and 5100 g mol^?1, 5900 g mol^?1, and 1.157, using NaOCl, respectively. According to TG analysis, the weight losses of 4‐MPIMP and P‐4‐MPIMP were found to be 85.37% and 72.19% at 1000°C, respectively. P‐4‐MPIMP showed higher stability against thermal decomposition. Also, electrical conductivity of the P‐4‐MPIMP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels and electrochemical energy gaps (E) of 4‐MPIMP and P‐4‐MPIMP were found to be ?5.76, ?5.19; ?3.00, ?3.24; 2.76 and 1.95 eV, respectively. According to UV–vis measurements, optical band gaps (E_g) of 4‐MPIMP and P‐4‐MPIMP were found to be 3.34 and 2.82 eV, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis of oligo‐ortho‐azomethinephenol and its oligomer–metal complexes: Characterization and application as anti‐microbial agents

The oxidative polycondensation reaction conditions and optimum parameters of o‐phenylazomethinephenol (PAP) with oxygen (air) and NaOCl were determined in an aqueous alkaline solution at 60–98°C. The properties of oligo‐o‐phenylazomethinephenol (OPAP) were studied by chemical and spectra analyses. PAP was converted to dimers and trimers (25–60%) by oxidation in an aqueous alkaline medium. The number average molecular weight (M_n), mass average molecular weight (M_w), and polydispersity index (PDI) values were 1180 g mol^?1, 1930 g mol^?1, and 1.64, respectively. According to these values, 20–33% of PAP turned into OPAP. During the polycondensation reaction, a part of the azomethine (? CH?N? ) groups oxidized to carboxylic (? COOH) group. Thus, a water‐soluble fraction of OPAP was incorporated in the carboxylic (? COOH); (2–20%) group. Also, the structure and properties of oligomer–metal complexes of OPAP with Cu(II), Ni(II), Zn(II), and Co(II) were studied. Antimicrobial activites of the oligomer and its oligomer–metal complexes were tested against B. cereus, L. monocytogenes, B. megaterium, B. subtilis, E. coli, Str. thermophilus, M. smegmatis, B. brevis, E. aeroginesa, P. vulgaris, M. luteus, S. aureus, and B. jeoreseens. Also, according to differential thermal analysis and thermogravimetric analysis, OPAP and its oligomer–metal complexes were stable throughout to temperature and thermo‐oxidative decomposition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2004–2013, 2002     

Schiff base‐substituted polyphenol: synthesis,characterisation and non‐isothermal degradation kinetics

BACKGROUND: Polymers of phenols and aromatic amines have emerged as new materials in fields such as superconductors, coatings, laminates, photoresists and high‐temperature environments. The stability, kinetics and associated pollution of the thermal decomposition of oligophenols are of interest for the aforementioned fields. RESULTS: A new Schiff base polymer, derived from N,N′‐bis(2‐hydroxy‐3‐methoxyphenylmethylidene)‐2,6‐pyridinediamine, was prepared by oxidative polycondensation. Characterisations using Fourier transform infrared, UV‐visible, ¹H NMR and ¹³C NMR spectroscopy, thermogravimetric/differential thermal analysis, gel permeation chromatography, cyclic voltammetry and conductivity measurements were performed. The number‐average (M_n) and weight‐average molecular weight (M_w) and dispersity (D = M_w/M_n) of the polymer were found to be 61 000 and 94 200 g mol^?1 and 1.54, respectively. Apparent activation energies of the thermal decomposition of the polymer were determined using the Tang, Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose and Coats–Redfern methods. The most likely decomposition process was a D_n deceleration type in terms of the Coats–Redfern and master plot results. CONCLUSION: The mechanism of the degradation process can be understood through the use of kinetic parameters obtained from various non‐isothermal methods. Copyright © 2009 Society of Chemical Industry     

Polyurethane foams with the contribution of products of hydroxyalkylation of N,N′‐bis(2‐hydroxyalkyl)oxamides with alkylene carbonates—obtaining and properties

In the reactions of N,N′‐bis(2‐hydroxyethyl)oxamide (BHEOD) with an excess of ethylene carbonate (EC) and N,N′‐bis(2‐hydroxypropyl)oxamide (BHPOD) with an excess of propylene carbonate (PC), the hydroxyethoxy and hydroxypropoxy derivatives of oxamide (OD) were obtained, respectively, distinguished by an increased thermal stability. First time, these derivatives were used as polyol components to obtain foamed polyurethane plastics with the contribution of 4,4′‐diisocyanate diphenylmethane (MDI). The rigid polyurethane foams of a slight water uptake, good stability of dimensions, enhanced thermal stability, and compression strength were obtained. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis,Characterization, and Thermal Degradation of Oligo-2-[(4-Chlorophenyl) Imino Methylene] Phenol and Its Oligomer-Metal Complexes

The oxidative polycondensation reaction conditions of 2-[(4-chlorophenyl) imino methylene] phenol (CPIMP) were studied by air O₂ and NaOCl oxidants at various temperatures and times. Optimum reaction conditions of air O₂ and NaOCl were determined for CPIMP. Oligo-2-[(4-chlorophenyl) imino methylene] phenol (OCPIMP) was synthesized from the oxidative polycondensation of CPIMP with air O₂ and NaOCl in alkaline medium between 50 and 90°C. The number-average molecular weight (M_n) weight-average molecular weight (M_w) and polydispersity index (PDI) values of OCPIMP were found to be 470 g mol^?1, 895 g mol^?1, and 1.90, using NaOCl, and 455 g mol^?1, 765 g mol^?1, and 1.68, using air O₂, respectively. At the optimum reaction conditions, the yield of OCPIMP was found to be 62.80% (for air O₂ oxidant) and 87.50% (for NaOCl oxidant). The OCPIMP was characterized by ¹H-NMR, FT-IR, UV-Vis and elemental analysis. The thermogravimetric (TGA)-DTA analyses were shown to be stable of OCPIMP and its oligomer metal complexes (such as Co⁺², Ni⁺², and Cu⁺²) against thermo-oxidative decomposition. The weight loss of OCPIMP and its oligomer metal complexes (such as Co⁺², Ni⁺², and Cu⁺²) were found to be 98%, 85%, 80%, and 82%, respectively, at 1000°C.     

Synthesis and thermal studies of poly(N‐acryloyl,N′‐cyanoacetohydrazide) complexes with Co(II), Fe(III), and UO2(II) ions

Polymer complexes with uranium, cobalt, and iron chlorides were synthesized and investigated by elemental analysis, electronic (uv–visible), IR vibration, and magnetic moment measurements. The thermal stabilities of N‐acryloyl,N′‐cyanoacetohydrazide (ACAH) homopolymers and polymer complexes of poly(ACAH) (PACAH) with metal chlorides were studied thermogravimetrically. The rates of polymerization of PACAH in the absence and presence of metal chlorides were studied. The activation energies of the degradation of the homopolymer and polymer complexes were calculated using the Arrhenius equation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3354–3358, 2003     

Synthesis of silver (nano)particle under hyperbranched poly(amido amine)s

Ag colloidal particles stabilized by poly (N,N′‐methylene bis‐acrylamide N‐aminoethyl piperazine) (MBA‐AEPZ) were prepared. The Ag⁺ ion concentration and reaction temperature were studied on the size and size distribution of Ag colloidal particles, which were determined from the ultraviolet (UV) plasmon absorption band and transmission electron microscopic (TEM) analyses. The data show that poly(MBA‐AEPZ) behaves like lower molecular mass stabilizers; some polymers surround the surface of the Ag colloidal particles and the particle size can be controlled by a change in the Ag⁺ ion concentration and reaction temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3701–3705, 2007     

Synthesis and characterization of novel benzhydrol-containing poly(amide-imide)s

A series of novel benzhydrol-containing poly(amide-imide)s (PAIs) have been prepared from a new diimide-dicarboxylic acid, N,N′-bis(4-hydroxycarbonyl)-benzhydrol-3,3′,4,4′-tetracarboxydiimide (BHTDA-DIA), with various diamines by direct polycondensation using triphenyl phosphite and pyridine as condensing agents. The polymers obtained had inherent viscosities of 0.35–0.96 dl g⁻¹. All these PAIs, except polymer PAI-2, were soluble in N-methyl-2-pyrrolidinone and N,N-dimethylacetamide containing LiCl (1 wt%). Tough and flexible PAI films could be obtained by casting PAIs from their DMAc or NMP solutions, except for polymer PAI-2. The polymer films had a tensile strength of 93–111 MPa, an elongation at break range of 4–6%, and an initial modulus range of 2.7–3.8 GPa. The glass transition temperatures of most polymers were found to be above 255 °C. These polymers were fairly stable up to a temperature around or above 400 °C, and lost 10% weight in the range 426–507 °C in nitrogen and 423–515 °C in air. © 1999 Society of Chemical Industry     

N,N′‐Pentamethylenethiuram disulfide‐ and N,N′‐pentamethylenethiuram hexasulfide‐accelerated sulfur vulcanization. I. Interaction of curatives in the absence of rubber

N,N′‐pentamethylenethiuram disulfide (CPTD), CPTD/sulfur, and N,N′‐pentamethylenethiuram hexasulfide (CPTP6) were heated in a DSC at a programmed heating rate and isothermally at 140°C. Residual reactants and reaction products were analyzed by HPLC at various temperatures or reaction times. CPTD rapidly formed N,N′‐pentamethylenethiuram monosulfide (CPTM) and N,N′‐pentamethylenethiuram polysulfides (CPTP) of different sulfur rank, CPTP of higher sulfur rank forming sequentially, as reported earlier for tetramethylthiuram disulfide (TMTD). As with TMTD, the high concentration of the accelerator monosulfide that develops is attributed to an exchange between CPTD and sulfenyl radicals, produced on homolysis of CPTD. However, a different mechanism for CPTP formation to that suggested for TMTD is proposed. It is suggested that disulfenyl radicals, resulting from CPTM formation, exchange with CPTD and/or CPTP already formed, to give CPTP of higher sulfur rank. CPTD/sulfur and CPTP6 very rapidly form a similar product spectrum with CPTP of sulfur rank 1–14 being detectable. Unlike with TMTD/sulfur, polysulfides of high sulfur rank did not form sequentially when sulfur was present, CPTP of all sulfur rank being detected after 30 s. It is proposed that sulfur adds directly to thiuram sulfenyl radicals. Recombination with sulfenyl radicals, which would be the most plentiful in the system, would result in highly sulfurated unstable CPTP. CPTP of higher sulfur rank are less stable than are disulfides as persulfenyl radicals are stabilized by cyclization, and the rapid random dissociation of the highly sulfurated CPTP, followed by the rapid random recombination of the radicals, would result in the observed product spectrum. CPTP is thermally less stable than is TMTD and at 140°C decomposed rapidly to N,N′‐pentamethylenethiourea (CPTU), sulfur, and CS₂. At 120°C, little degradation was observed. The zinc complex, zinc bis(pentamethylenedithiocarbamate), did not form at vulcanization temperatures, although limited formation was observed above 170°C. ZnO inhibits degradation of CPTD to CPTU. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2718–2731, 2000     

Analysis of the reaction course of oxamide and N,N′‐bis(2‐hydroxypropyl)oxamide with propylene carbonate

Studies on obtaining and hydroxypropyl properties of oxamide (OD) derivatives with contribution of OD and N,N′‐bis(2‐hydroxypropyl)oxamide (BHPOD) were carried out. As a hydroxyalkylating agent, the propylene carbonate (PC) was used. Hydroxypropylating with OD proceeds with a partial preservation of carbonate groups in the structure of products, and during the reaction, a partial dimerization of hydroxypropoxylene derivatives of OD occurs. The obtained hydroxypropoxy derivatives of OD are distinguished by an increased thermal stability. Hydroxypropoxy derivatives of OD are expected to find application as polyol components for the manufacture of thermally stable foamed polyurethane plastics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis,characterization, and kinetic of thermal degradation of oligo‐2‐[(4‐bromophenylimino)methyl]phenol and oligomer‐metal complexes

Oligo‐2‐[(4‐bromophenylimino)methyl]phenol (OBPIMP) was synthesized from the oxidative polycondensation reaction of 2‐[(4‐bromophenylimino)methyl]phenol (BPIMP) with air and NaOCl oxidants in an aqueous alkaline medium between 50 and 90°C. The yield of OBPIMP was found to be 67 and 88% for air and NaOCl oxidants, respectively. Their structures were confirmed by elemental and spectral such as IR, ultraviolet–visible spectrophotometer (UV–vis), ¹H‐NMR, and ¹³C‐NMR analyses. The characterization was made by TG‐DTA, size exclusion chromatography, and solubility tests. The resulting complexes were characterized by electronic and IR spectral measurements, elemental analysis, AAS, and thermal studies. According to TG analyses, the weight losses of OBPIMP, and oligomer‐metal complexes with Co⁺², Ni⁺², and Cu⁺² ions were found to be 93.04%, 59.80%, 74.23%, and 59.30%, respectively, at 1000°C. Kinetic and thermodynamic parameters of these compounds investigated by Coats‐Redfern, MacCallum‐Tanner, and van Krevelen methods. The values of the apparent activation energies of thermal decomposition (E_a), the reaction order (n), preexponential factor (A), the entropy change (ΔS*), enthalpy change (ΔH*), and free energy change (ΔG*) obtained by earlier‐mentioned methods were all good in agreement with each other. It was found that the thermal stabilities of the complexes follow the order Cu(II) > Co(II) > Ni(II). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The synthesis and characterization of oligo-N-4-aminopyridine, oligo-2-[(pyridine-4-yl-imino) methyl] phenol and its some oligomer-metal complexes

The product and the oxidative polycondensation reaction conditions of oligo-4-aminopyridine were studied by using NaOCl as oxidant. Oligo-4-aminopyridine (4-OAP) was synthesized from the oxidative polycondensation of 4-aminopyridine (4-AP) in an aqueous solution medium acidic and neutral between 25 and 60 °C by using NaOCl as oxidant. About 85% of 4-AP was converted to 4-OAP. The number average molecular weight, (M_n) mass average molecular weight (M_w) and polydispersity index (PDI) values of 4-OAP synthesized were found to be 270, 850 g mol⁻¹ and 3.15, respectively, using NaOCl. The respective values of the Schiff base were 1721, 2256 g mol⁻¹ and 1.31, respectively, using air oxygen and 2173, 2372 g mol⁻¹ and 1.09, respectively, using NaOCl and 2749, 6432 g mol⁻¹ and 2.33, respectively, using H₂O₂. At the optimum reaction conditions, the yield of oligo-2-[(pyridine-4-yl-imino) methyl] phenol (OPMP) were found to be 86% (H₂O₂) and 89% (NaOCl) and 95% (air oxygen). The 4-OAP and OPMP were characterized by ¹H NMR, FT-IR, UV-Vis and elemental analysis. TG analysis showed to be stable of 4-OAP against thermo-oxidative decomposition. The weight loss of 4-OAP and its Schiff base oligomer was found to be 50, 86.39 and 71.78% at 525, 625 and 1000 °C, respectively. Also, new oligomeric Schiff base was synthesized from condensation of 4-AP with salicylaldehyde and their structures and properties were determined. During polycondensation reaction, a part of the azomethine (-CHN-) groups oxidized to carboxylic (-COOH) group. Thus, soluble fraction in water of oligo-2-[(pyridine-4-yl-imino) methyl] phenol involved in carboxylic (-COOH) (11%) group. Besides, the structure and properties of oligomer-metal complexes of oligo-2-[(pyridine-4-yl-imino) methyl] phenol (OPMP) with Cu(II), Ni(II) and Co(II) were studied.     

The oxidative polycondensation of 2-[(4-pyridilmethylene)-imino]phenol by molecular O2 in alkaline medium: Synthesis and characterization

Summary The polymer of 2-[(4-pyridilmethylene)-imino] phenol (2-PIP) has been formed from the oxidative polycondensation (OP) reaction by using molecular O₂ as the oxidant in an aqueous alkaline medium between 60–90 °C. The optimum reaction conditions and the main parameters of the process were determined. The yield of polymer was found as 50.1%. The structures of synthesized monomer and polymer were confirmed by FT-IR, UV-vis, ¹H-¹³C-NMR and elemental analysis. The characterization was made by TGA-DTA, size exclusion chromatography (SEC) and solubility tests. The ¹H-¹³C-NMR data shows that the polymerization proceeded with C-C and C-O-C coupling system of ortho and para positions and oxyphenylene according to –OH group of 2-PIP. The molecular weight distribution values of the product were determined from SEC measurement. The number-average molecular weight (M_n), weight-average molecular weight (M_w) and polydispersity index (PDI) values of poly-2-[(4-pyridilmethylene)-imino]phenol (poly-2-PIP) were found to be 11350, 12600 g.mol^-1 and 1.110, respectively. According to thermo gravimetric analysis (TGA), the carbon residues of 2-PIP and poly-2-PIP were found to be 18.17% and 45.10%, respectively, at 1000 °C.     

Synthesis, characterization and optimum reaction conditions of oligo-2-amino-3-hydroxypyridine and its Schiff base oligomer

The oxidative polycondensation reaction conditions of 2-amino-3-hydroxypyridine (AHP) and 2-[benzilydeneimino] pyridine-3-ol (BIP) were studied by oxidants such as with air O₂, NaOCl and H₂O₂. Oligo-2-amino-3-hydroxypyridine (OAHP) was synthesized from the oxidative polycondensation of AHP with air O₂, NaOCl and H₂O₂ in an aqueous acidic and alkaline medium at 30-90 °C. BIP was synthesized from condensation of 2-amino-3-hydroxypyridine with benzaldehyde. Oligo-2-[benzilydeneimino] pyridine-3-ol (OBIP) was synthesized from the oxidative polycondensation of BIP with air O₂, NaOCl and H₂O₂ in an aqueous alkaline medium at 40-90 °C. About 95% BIP was converted to OBIP. The number average molecular weight, (M_n) weight average molecular weight (M_w) and polydispersity index (PDI) values of OAHP and OBIP (for air O₂ oxidant) were found to be 1433, 1912 g mol⁻¹, 1.33 and 2637, 5106 g mol⁻¹ and 1.94, respectively. At the optimum reaction conditions, the yield of OAHP was found to be 86.0% (for air O₂ oxidant), 43.0% (for H₂O₂ oxidant) and 85.0% (for NaOCl oxidant). At the optimum reaction conditions, the yield of OBIP was found to be 91.0% (for air O₂ oxidant), 92.0% (for H₂O₂ oxidant) and 95.0% (for NaOCl oxidant). The OHAP and OBIP were characterized by FT-IR, UV-Vis, ¹H and ¹³C-NMR elemental analysis. TG and DTA analyses were shown to be unstable of OAHP and OBIP against thermo-oxidative decomposition. According to TG analyses, the weight loss of OAHP and OBIP was found to be 97.35 and 96.60% at 520 and 685 °C, respectively.     

Synthesis,Structure, and Properties of N,N′‐Dinitrourea

Information on synthesis methods and properties of N,N′‐dinitrourea and its salts, which were reported virtually simultaneously by different authors in different publications, is summarized and systematized. Merits and drawbacks of various approaches for the synthesis of the target products are discussed. The reactivity of N,N′‐dinitrourea and its salts in the reactions of nucleophilic substitution and condensation is discussed.     

Synthesis and chemical modification of poly(divinylsiloxane)

Hexavinylcyclotrisiloxane(I) has been prepared by reaction of divinyldichlorosilane with DMSO and triethylamine. Anionic ring-opening polymerization (AROP) of I catalyzed by dilithio diphenylsilanediolate yields high molecular weight poly(divinylsiloxane)(II) with a narrow molecular weight distribution. Similarly, narrow molecular weight distribution poly(vinylmethylsiloxane)(III) has been prepared by AROP of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane(IV) initiated by dilithio diphenylsilanediolate. On the other hand, III which has a broad molecular weight distribution has been synthesized by AROP of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane(V) catalyzed by phosphazene P₄-t-Bu superbase. Chemical modification of the C-C double bonds of II and III has been achieved by Pt-catalyzed hydrosilylation with 3,3,3-trifluoropropyldimethylsilane(VI) or 1H,1H,2H,2H-perfluorooctyldimethylsilane(VII). While Pt-catalyzed hydrosilylation reactions usually proceed in a regioselective anti-Markovnikov manner, Markovnikov addition is competitive in these examples.     

Synthesis,characterization, conductivity,band gap,and kinetic of thermal degradation of poly‐4‐[(2‐mercaptophenyl) imino methyl] phenol

The oxidative polycondensation reaction conditions of 4‐[(2‐mercaptophenyl) imino methyl] phenol (2‐MPIMP) were studied in an aqueous acidic medium between 40 and 90°C by using oxidants such as air, H₂O₂, and NaOCl. The structures of the synthesized monomer and polymer were confirmed by FTIR, ¹H NMR, ¹³C NMR, and elemental analysis. The characterization was made by TGA‐DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of poly‐4‐[(2‐mercaptophenyl) imino methyl]phenol (P‐2‐MPIMP) was found to be 92% for NaOCl oxidant, 84% for H₂O₂ oxidant 54% for air oxidant. According to the SEC analysis, the number‐average molecular weight (M_n), weight‐average molecular weight (M_w), and polydispersity index values of P‐2‐MPIMP were found to be 1700 g mol^?1, 1900 g mol^?1, and 1.118, using H₂O₂; 3100 g mol^?1, 3400 g mol^?1, and 1.097, using air; and 6750 g mol^?1, 6900 g mol^?1, and 1.022, using NaOCl, respectively. According to TG analysis, the weight losses of 2‐MPIMP and P‐2‐MPIMP were found to be 95.93% and 76.41% at 1000°C, respectively. P‐2‐MPIMP showed higher stability against thermal decomposition. Also, electrical conductivity of the P‐2‐MPIMP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital, the lowest unoccupied molecular orbital, and the electrochemical energy gaps (E′_g) of 2‐MPIMP and P‐2‐MPIMP were found to be ?6.13, ?6.09; ?2.65, ?2.67; and 3.48, 3.42 eV, respectively. Kinetic and thermodynamic parameters of these compounds investigated by MacCallum‐Tanner and van Krevelen methods. The values of the apparent activation energies of thermal decomposition (E_a), the reaction order (n), pre‐exponential factor (A), the entropy change (ΔS*), enthalpy change (ΔH*), and free energy change (ΔG*) were calculated from the TGA curves of compounds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and properties of poly(amide–imide)s based on N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide,p‐aminobenzoic acid and various aromatic diamines

A new diimide–diacid monomer, N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide (I), was prepared by azeotropic condensation of 4,4′‐oxydiphthalic anhydride (ODPA) and p‐aminobenzoic acid (p‐ABA) at a 1:2 molar ratio in a polar solvent mixed with toluene. A series of poly(amide–imide)s (PAI, III_a–m) was synthesized from the diimide–diacid I (or I′, diacid chloride of I) and various aromatic diamines by direct polycondensation (or low temperature polycondensation) using triphenyl phosphite and pyridine as condensing agents. It was found that only III_k–m having a meta‐structure at two terminals of the diamine could afford good quality, creasable films by solution‐casting; other PAIs III using diamine with para‐linkage at terminals were insoluble and crystalline; though III_g–i contained the soluble group of the diamine moieties, their solvent‐cast films were brittle. In order to improve their to solubility and film quality, copoly(amide–imide)s (Co‐PAIs) based on I and mixtures of p‐ABA and aromatic diamines were synthesized. When on equimolar of p‐ABA (m = 1) was mixed, most of Co‐PAIs IV had improved solubility and high inherent viscosities in the range 0.9–1.5 dl g^?1; however, their films were still brittle. With m = 3, series V was obtained, and all members exhibited high toughness. The solubility, film‐forming ability, crystallinity, and thermal properties of the resultant poly(amide–imide)s were investigated. © 2002 Society of Chemical Industry     

New photosensitive poly(amid‐imide)s containing chalcone moiety and hydantoin derivatives in the main chain: Synthesis and characterization

Six new poly(amid‐imide)s containing chalchone and hydantoin moieties in the main chain were synthesized through the polycondensation reaction of 1,3‐bis[4,4′‐bis(trimellityimido)phenyl]‐2‐propenone 6 with six hydantoin derivatives 7a‐f in a medium consisting of triphenyl phosphite, calcium chloride, pyridine, and N‐methyl‐2‐pyrrolidone. The polycondensation reaction produced a series of novel poly(amid‐imide)s 8a‐f in high yields with inherent viscosities between 0.26 and 0.42 dL/g. The resulting polymers were characterized by elemental analysis, viscosity measurements, solubility test, thermo gravimetric analysis (TGA and DTG), FTIR, and UV‐Vis spectroscopy. 1,3‐bis[4,4′‐bis(trimellityimido)phenyl]‐2‐propenone 6 was prepared from a three‐step reaction by using 4‐nitro benzaldehyde 1 and 4‐nitro acetophenone 2 as precursors. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Highly Enantioselective Allylation of Aromatic α‐Keto Phosphonates Catalyzed by Chiral N,N′‐Dioxide‐Indium(III) Complexes

The ramipril derivative N,N′‐dioxide 3g ‐indium(III) complex was found to be an efficient catalyst for the allylation of the aromatic α‐keto phosphonates. The corresponding α‐hydroxy phosphonates were obtained with high yields (up to 98 %) and high enantioselectivities (up to 91 % ee). A bifunctional catalyst system was described with an N‐oxide as Lewis base activating tetraallyltin and indium as Lewis acid activating aromatic α‐keto phosphonates. A possible catalytic cycle has been proposed to explain the mechanism of the reaction.