Danuta Sek

New Conjugated Azomethines Containing Triphenylamine Core —Characterization and Properties

A novel polyazomethines bearing triphenylamine core and a proper model compound were synthesized and their spectroscopic (FTIR, 1 H NMR) and optical (UV-vis, photoluminescence) properties and also a molecular dynamic calculations were investigated. The polymers which were soluble in organic solvents (chloroform, dimethylacetamide, m-cresol) and formed transparent foils, emitted blue light and their photoluminescence band and intensity were solvent dependent. Additionally, the effects of blending the new polyazomethines with other polymers—PMMA, polyvinylophenol on UV-vis spectra were examined. Non-covalent ionic-type interactions between azomethines and methanesulfonic acid (MSA), m-cresol (MC) and p-chlorophenol (pClp) were also investigated. The structure formation of azomethines complexes are discussed on the basis of 1H NMR and FTIR. Photoluminescence and absorption properties of the azomethines compounds after doping with MSA, MC and pClp were tested.

New Soluble Polyimides Containing Hydroxylic Groups: I. Synthesis and characterization

A series of aromatic polyimides from different diamidedianhydrides and 2,4-diaminophenol dihydrochloride was synthesized using a one-step high-temperature polycondensation. The structural characterization of the prepared polyimides was carried out by using Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. The influence of the monomers’ structures on the polymers’ properties has been investigated.

Synthesis and characterization of organosoluble aliphatic–aromatic copolyimides based on cycloaliphatic dianhydride

Abstract A series of aliphatic–aromatic polyimides have been synthesized. These polyimides were prepared by high-temperature polycondensation of the aliphatic diamines: 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,9-diaminononane, 1,10-diaminodecane, 1,12-diaminododecane and 4,4 ′ -methylenebis(2,6-dimethylaniline) with 1,2,3,4-cyclopentanetetracarboxylic dianhydride. Various ratios of diamines (aromatic:aliphatic) have been applied for preparation of copolyimides. Polycondensation proceeded at 190 °C and produced copolyimides with reduced viscosities up to 0.92 dl/g. The polyimides were soluble in a wide range of organic, common solvents and showed high-thermal stability. In most cases these polymers formed flexible films which presented excellent transparency.

Investigation of polyimides containing naphthalene units. III. Influence of monomers structure on polymers properties

A series of polymers from dinaphthalene dianhydrides and aromatic diamines has been synthesized using one-step high-temperature polycondensation. The influence of the monomers structure on the polymers properties has been investigated.

Characteristic and spectroscopic properties of the Schiff-base model compounds

Two series of conjugated aromatic imines (Schiff-base model compounds) with different central groups and various side-group substitutions have been synthesized and characterized by elemental analysis, differential scanning calorimetry (DSC) technique, hydrogen nuclear magnetic resonance ((1)H NMR), Fourier transform infrared (FTIR) and ultra-violet and visible light (UV-vis) spectroscopy measurements. The UV-vis absorption of solutions of these compounds in dimethylacetamid (DMA), chloroform and methanol was investigated in the optical range from 240 to 450nm, where two distinct absorption bands: at 250-280 and 315-360nm with the different level of absorption have been observed. The influence of compound molecular structure and polarity of solvent on the absorption spectra and the possible optical transitions have been discussed. Structure of diamines in the azomethine models fundamentally affected their spectroscopic properties and conjugation of pi-electrons.

New semiladder polymers. Part II: Synthesis and properties of new poly(amideimidazopyrrolones)

Abstract A series of polymers from new diamidedianhydrides of arylene-di(benzene-5-amido-1,2-dicarboxylic) anhydride type and aromatic tetraamines (3,3′-diaminobenzidine and 3,3′,4,4′-tetraaminodiphenylether) were synthesized using one step high temperature polycondensation in m -cresol and p -chlorophenol at 180°C and low temperature polycondensation. The polymers had a semiladder structure. The influence of the monomer structure and polycondensation method on the polymer properties has been investigated.

Opto(electrical) properties of triphenylamine-based polyazomethine and its blend with [6,6]-phenyl C61 butyric acid methyl ester

Polyazomethine (OFBF-TPA) based on triphenylamine (TPA) and octafluorobiphenyl (OFBF) moieties was tested as donor–acceptor (D-A) for bulk heterojunction polymeric solar cells. The temperatures of 5% weight loss (T 5%) of the polyazomethine range from 323 to 328°C, depending on the gas used (air and nitrogen). The conductivity of OFBF-TPA was approximately 10−10 S/cm for not annealed sample and at about 10−6 S/cm for the ones annealed at room temperature, as determined by impedance spectroscopy. Surface of the polymer and mixture polymer–[6,6]-phenyl C61 butyric acid methyl ester (PCBM) was smooth with the R ms value in the range 0.58–1.95 nm as was detected by the atomic force microscopy (AFM) technique. UV-vis spectrum of the mixture OFBF-TPA-PCBM exhibited higher absorption intensity than the UV-vis spectrum of OFBF-TPA lacking PCBM. The thin solid film of OFBF-TPA and OFBF-TPA-PCBM showed one main absorption band with a maximum peak at 414 and 411 nm, respectively. For the mixture OFBF-TPA-PCBM, the second absorption band at 333 nm was found. No influence of annealing on the absorption properties was observed. The polymer solar cell devices were fabricated by spin coating the blend solution of the OFBF-TPA and PCBM and investigated in dark and under an illumination of 100 mW/cm2, with an AM1.5 G. Electrical behavior of the device indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) (PEDOT)- poly(styrenesulfonate) (PSS)/OFBF-TPA-PCBM/Al was tested by impedance spectroscopy in dark and under illumination. For all measured devices, Nyquist plots were presented. The annealing significantly improved the electrical conductivity of the investigated devices. Electrical and photovoltaic properties of OFBF-TPA were compared with the properties of polyazomethine based on TPA and fluorene moieties (F-TPA).

Comparative studies of structural, thermal, optical, and electrochemical properties of azines with different end groups with their azomethine analogues toward application in (opto)electronics.

Two series of azines and their azomethine analogues were prepared via condensation reaction of benzaldehyde, 2-hydroxybenzaldehyde, 4-pyridinecarboxaldehyde, 2-thiophenecarboxaldehyde, and 4-(diphenylamino)benzaldehyde with hydrazine monohydrate and 1,4-phenylenediamine, respectively. The structures of given compounds were characterized by FTIR, (1)H NMR, and (13)C NMR spectroscopy as well as elemental analysis. Optical, electrochemical, and thermal properties of all compounds were investigated by means of differential scanning calorimetry (DSC), UV-vis spectroscopy, stationary and time-resolved photoluminescence spectroscopy, and cycling voltammetry (CV). Additionally, the electronic properties, that is, orbital energies and resulting energy gap were calculated theoretically by density functional theory (DFT). Influence of chemical structure of the compounds on their properties was analyzed.

Synthesis of PP–LCP graft copolymers and their compatibilizing activity for PP/LCP blends

The aim of this work was the synthesis of new graft copolymers consisting of polypropylene (PP) backbones and liquid crystalline polymer (LCP) branches, to be used as compatibilizing agents for PP/LCP blends. The PP-g-LCP copolymers have been prepared by polycondensation of the monomers of a semiflexible liquid crystalline polyester (SBH 1 : 1 : 2), that is, sebacic acid (S), 4,4′-dihydroxybiphenyl (B), and 4-hydroxybenzoic acid (H) in the mole ratio of 1 : 1 : 2, carried out in the presence of appropriate amounts of a commercial acrylic-acid-functionalized polypropylene (PPAA). The polycondensation products, referred to as COPP50 and COPP70, having a calculated PPAA concentration of 50 and 70 wt %, respectively, have been fractionated with boiling toluene and xylene, and the soluble and insoluble fractions have been characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry, and X-ray diffraction. All analytical characterizations have concordantly shown that the products are formed by intricate mixtures of unreacted PPAA and SBH together with PP-g-SBH copolymers of different composition. Exploratory experiments carried out by adding small amounts of COPP50 or COPP70 into binary mixtures of isotactic polypropylene (iPP) and SBH while blending have demonstrated that this practice leads to an appreciable improvement of the dispersion of the minor LCP phase, as well as to an increase of the crystallization rate of iPP.

New semiladder polymers: 1. Synthesis and properties of new poly(esterimidazopyrrolone)s

Abstract A series of polymers formed from diesterdianhydrides of arylene-di(benzene-5-estro-1,2-dicarboxylic) anhydride type and tetraamines, 3,3′diaminobenzidine and 3,3′,4,4′tetraaminodiphenyl ether, has been synthesized using one-step high temperature polycondensation in m-cresol at 180°C. The relation between polymer reduced viscosity and reaction time was studied and structures of the polymers were detected by FTi.r. spectroscopy.