Six new dicarboxylic acids 3a-f were synthesized by the reaction of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) 1 with L-amino acids 2a-f in a solution of glacial acetic acid/pyridine (Py) at refluxing temperature. Then six new optically active poly(amide-imide)s (PAI)s with good inherent viscosities were synthesized by direct polycondensation reaction of [N,N'-(4,4'-diphtaloyl)-bis-L-amino diacid]s with 1,2-bis[4,4'-aminophenoxy] ethane (APE) 4 in a medium of N-methyl-2-pyrrolidone (NMP)/ triphenyl phosphite (TPP)/ calcium chloride (CaCl2)/pyridine. Not only PAIs are optically active but also soluble in various organic solvents. These resulting new polymers can be used in column chromatography for the separation of enantiomeric mixtures. The resulted polymers were fully characterized by means of FTIR, ¹H-NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation, solubility tests and UV-Vis spectroscopy. Also thermal properties of the PAIs 3a-f were investigated using thermal gravimetric analysis (TGA).

A series of nanocomposites consist of organic polyimide and organo-modified clay content varying from 0 to 5 wt%, were successfully prepared by in situ polymerization. Polyimide used as a matrix of nanocomposite was prepared through the reaction of 1,4-bis [4-aminophenoxy] butane (APB) and 3،3΄،4،4΄-benzophenone tetra carboxylic dianhydride (BTDA) in N,N-dimethylacetamide (DMAc). The resulting nanocomposite films were characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).

Se preparó una serie de nanocompuestos consistentes en poliimidas y arcillas modificadas con grupos orgánicos, en los que se varió el contenido de arcilla modificada, de 0 a 5% en peso; La poliimida utilizada como matriz del nanocompuesto se preparó mediante la reacción de 1,4-bis [4-aminofenoxi] butano y el dianhídrido carboxílico 3,3,4,4-tetra benzofenona en N,N-dimetilacetamida (DMAC). Las películas de nanocompuestos resultantes se caracterizaron por espectroscopía FT-IR, difracción de rayos X (XRD), microscopía electrónica de barrido y análisis termogravimétrico.

A new poly(amide-imide)-montmorillonite series were generated through solution intercalation technique. Cloisite® 20A was used as a modified montmorillonite for ample compatibility with the poly(amide-imide) (PAI) matrix. The PAI 5 chains were synthesized by the direct polycondensation reaction of N-trmiellitylimido-L-alanine (3) with 4,4'-diamino diphenyl ether (4) in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films 5a-5d with (5-20 Wt%) silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposites films were investigated by using UV-Vis spectroscopy, thermogravimetric analysis (TGA), and water uptake measurements.

Se generó una nueva serie de montmorillonita poliamido-imidas a través de la técnica de intercalación en solución. Como montmorillonita se empleó Cloisite® 20A con gran compatibilidad con la matriz de poli(amido-imido) (PAI). Las cadenas de PAI 5 se sintetizaron por reacción de policondensación directa de la N-trimellitilimido-L-alanina (3) con éter 4,4'-diaminodifenílico (4) en presencia de trifenilfosfita (TPP), CaCl2, piridina y N-metil-2-pirrolidona (NMP). La morfología y estructura de las películas de PAI-nanocomposita con partículas de silicato (5-20% peso), 5a-5d, se caracterizaron por espectroscopia FTIR, difracción de rayos X (XRD) y microscopia electrónica de barrido (SEM). Se investigaron, mediante espectroscopia UV-Vis, análisis termogravimétrico (TGA) y mediciones de absorción de agua, tanto el efecto de la dispersión de la arcilla como la interacción entre la arcilla y las cadenas poliméricas sobre las propiedades de las películas nanocompositas.

A new polyimide-silver nanocomposite containing diphenyl sulfone moiety in the main chain was synthesized using a convenient ultraviolet irradiation technique.AgNO3 was used as a source of the silver nanoparticles. Polyimide 3, as a polymer source , was synthesized by the polycondensation reaction of 4,4'-diamino diphenyl sulfone 1 with pyromellitic anhydride 2 in the presence of iso-quinoline as base and m-cresol as solvent. The resulting composite film 3a was characterized by FTIR spectroscopy, Uv-vis analysis, X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). The X-ray diffraction analysis reveals that silver nanoparticles are present in polyimide matrix. This data is in good agreement with the result obtained from TEM and shows the silver nanoparticles homogeneously dispersed in the polyimide matrix. The UV-vis spectrum shows a single peak at 425 nm, arising from the surface plasmon absorption of the silver nanoparticles.

A new series of optically active and thermally stable poly(amide-imide)s (PAIs) with good inherent viscosities based on bicyclo diacids and etheric diamine in the main chain were synthesized from the direct polycondensation reaction of AW'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-g with 1,2-Bis[4-aminophenoxy]ethane 7 by direct polycondensatios with two different media such as direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride (CaCl2)/pyridine (Py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (Py)/N,N-dimethylformamide (DMF) system. Also 3a-g were synthesized by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 1 with two equimolars of various amino acids such as L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenylalanine 2e, L-2-aminobutyric acid 2f and L-histidine 2g in an acetic acid solution. The polymerization reactions produced a series of thermally stable and optically active organosoluble PAIs. The resulting polymers were fully characterized by means of FT-IR and ¹H-NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation, solubility tests and differential scanning calorimeter (DSC). Also thermal properties of the PAIs 8a-g were investigated using thermal gravimetric analysis (TGA) and derivative of thermaogravimetric (DTG) analysis.

A new series of copolyamides CoPAs 7a-f were synthesized through the direct polycondensation reaction of 4,4'-azobenzenedicarboxylic acid 1 with 1,5-naphthalenediamine 2, 3,4-diaminobenzophenone 3 in the presence of adipic acid 4, fumaric acid 5 and terephthalic acid 6 as a second diacid in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosphate (TPP), calcium chloride and pyridine. The obtained polymers were characterized by means of FT-IR spectroscopy, elemental analyses and inherent viscosity. These CoPAs were highly soluble in polar aprotic solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), W-methyl-2-pyrrolidone (NMP) and other solvents such as sulfuric acid. Thermal properties of the CoPAs 7 c, 7d and 7e were investigated using thermal gravimetric analysis (TGA and DTG).

Six new thermally stable polyamides 3a-f were synthesized through the polycondensation reaction of 2,5-pyridine dicarboxylic acid 1 with six different derivatives of aromatic diamines 2a-f in amedium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride and pyridine. The polycondensation reaction produced a series of novel polyamides containing pyridyl moieties in the main chain in high yield with inherent viscosities between 0.50-0.82 dL/g. The resulting polymers were fully characterized by means of FT-IR spectroscopy, elemental analyses, inherent viscosimetry, and solubility tests. Thermal properties of these polymers were investigated by using thermal gravimetric analysis (TGA) and differantional thermal gravimetry (DTG). All of the polymers were soluble at room temperature in polar solvents such as N,N'-dimethyl acetamide, N,N'-dimethyl formamide, dimethyl sulfoxide and N-methy1-2-pyrrolidone.

Cinco novas poliamidas-iminas (PAIs) oticamente ativas 6a-e foram preparadas pela reação de policondensação direta da N,N´-(biciclo[2,2,2]octa-7-eno-2,3,5,6-tetracarboxila)-bis-L-alanina 4 com várias diaminas aromáticas 5a-e usando solventes polares apróticos como a N-metil-2-pirrolidona (NMP). Neste procedimento, trifenil fosfito (TPP) e piridina foram usados como agentes de condensação para formar poliamidas-imidas através dos sais de N-fosfônio-piridina. Todos os polímeros foram obtidos com rendimentos quantitativos com uma viscosidade intrínseca entre 0,29-0,46 dL g-1, sendo altamente solúveis em solventes polares apróticos como N,N-dimetil acetamida (DMAc), N,N-dimetilformamida (DMF), dimetil sulfóxido (DMSO), N-metil-2-pirrolidona (NMP) e ainda em solventes como o ácido sulfúrico. Os compostos foram caracterizados por espectroscopia de RMN ¹H, espectroscopia no infravermelho, análise elementar, viscosidade intrínseca, testes de solubilidade, rotação específica e as propriedades térmicas desses polímeros foram investigadas usando técnicas termogravimétricas de análise (TGA e DTG).

Five new optically active poly(amide-imide)s (PAIs) 6a-e were prepared by direct polycondensation reaction of the newly synthesized N,N´-(bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetra carboxylic)-bis-L-alanine 4 with various aromatic diamines 5a-e using polar aprotic solvents such as N-methyl-2-pyrrolidone (NMP). In this technique triphenyl phosphite (TPP) and pyridine were used as condensing agents to form poly(amide-imide)s through the N-phosphonium salts of pyridine. All of the polymers were obtained in quantitative yields with inherent viscosities between 0.29-0.46 dL g-1 and were highly soluble in polar aprotic solvents such as N,N-dimethyl acetamide (DMAc), N,N-dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP) and solvents such as sulfuric acid. They were fully characterized by means of ¹H NMR, FTIR spectroscopy, elemental analyses, inherent viscosity, solubility test, specific rotation and thermal properties of these polymers were investigated using thermogravimetric analysis techniques (TGA and DTG).