Synthesis, Characterization, Thermal Stability and Conductivity of New Schiff Base Polymer Containing Sulfur and Oxygen Bridges

Abstract

In this study, we proposed to synthesize thermally stable, soluble and conjugated Schiff base polymer (SbP). For this reason, a specific molecule namely 4,4'-thiodiphenol which has sulfur and oxygen bridge in its structure was used to synthesize bi-functional monomers. Bi-functional amino and carbonyl monomers namely 4,4'-[thio-bis(4,1-phenyleneoxy)]dianiline (DIA) and 4,4'-[thiobis(4,1-phenyleneoxy)]dibenzaldehyde (DIB) were prepared from the elimination reaction of 4,4'-thiodiphenol with 4-iodonitrobenzene and 4-iodobenzaldehyde, respectively. The structures of products were confirmed by elemental analysis, FTIR, 1 H NMR and 13 C NMR techniques. The molecular weight distribution parameters of SbP were determined by size exclusion chromatography (SEC). The synthesized SbP was characterized by solubility tests, TG-DTA and DSC. Also, conductivity values of SbP and SbP-iodine complex were determined from their solid conductivity measurements. The conductivity measurements of doped and undoped SbP were carried out by Keithley 2400 electrometer at room temperature and atmospheric pressure, which were calculated via fourpoint probe technique. When iodine was used as a doping agent, the conductivity of SbP was observed to be increased. Optical band gap (E g ) of SbP was also calculated by using UV-Vis spectroscopy. It should be stressed that SbP was a semiconductor which had a potential in electronic and optoelectronic applications, with fairly low band gap. SbP was found to be thermally stable up to 300 o C. The char of SbP was observed 29.86% at 1000 o C.

Synthesis of Poly(azomethine) Containing Sulfonic Acid Unit Oxygen and Sulphur Bridged: Investigation of Its Thermal, Optical and Electrochemical Properties

“…After the analysis using the two-probe technique, the conductivity value of SBP was calculated as 2.35 x 10 -10 S/cm. Since it was stated in the studies that the conductivity values of undoped poly(azomethine) compounds were generally observed in the range of 1 x 10 -9 -1 x 10 -11 S/cm, the result was found to be compatible with previous studies [22]. Therefore, it turned out that the conductivity of the obtained SBP was low.…”

“…DBA, a dibenzaldehyde compound obtained from the bromine elimination reaction from 4,4'-thiodiphenol and bromo-benzaldehyde, was examined by FTIR spectroscopy. In a study by Culhaoğlu and [22], the FT-IR spectra of this synthesized substance were compared and it was observed that the spectra were compatible with each other. FT-IR spectra of synthesized DBA and SBP are shown in Figure 2…”

“…DBA was obtained by bromine elimination reaction by using 4-bromobenzaldehyde instead of 4iodobenzaldehyde using the method given in the literature [22]. 1.091 g (0.005 mol) of 4,4'-thiodiphenol was dissolved in 15 mL of DMA in a 100 mL threenecked flask.…”

Thermal Analysis Study of Modified Urea-Formaldehyde Resin

“…[2][3][4][5] As a powerful technique for studying the pyrolysis mechanism of physicochemical processes, thermal analysis mainly includes differential scanning analysis (DTA), thermomechanical analysis (TMA), differential thermal gravity (TG/DTG) and differential scanning calorimetry (DSC). [6][7][8][9] The last two kinds are the most widely used approach for studying pyrolytic reaction of thermosetting resin. [10][11][12][13] In most thermal decomposition kinetic research methods, Kissinger's 14 maximum weight-loss rate method and Ozawa's 15 equivalent weight-loss percentage method are applied for dynamic computation via relation between peak temperature and heating rate of DTG and DSC curves, involving no selection of mechanism func-폴리머, 제40권 제5호, 2016년 tion and applying to any reaction order with more reliable result.…”

New Fluorescent, Thermally Stable and Film Forming Polyimines Containing Naphthyl Rings

“…S3-S5), similar assignments have been reported in the literature for dicarbonyl monomers. 36,37 The polymers PmHOBND and PoHONPD showed weak band at 1694 and 1683 cm -1 respectively for υ C=O contributed from end on group, this band was present as a strong band in their corresponding monomers which showed that carbonyl group was converted into imine group. All the three polymers (PmHOBND, PoHONPD and PoHOAND) showed strong to medium intensity band within 1594-1620 cm -1 for υ C=N and the band within 1592-1518 cm -1 due to aromatic rings of the polymers.…”