Search results

1 – 4 of 4
Article
Publication date: 24 May 2011

Nilgün Kızılcan, Banu Hocaoğlu and Belkıs Ustamehmetoğlu

The purpose of this paper is to synthesise cyclohexanone formaldehyde resin (CFR)‐modified carbazole‐9‐carbonyl chloride (CzCl) via hydroxyl groups of CFR. This carbazole‐modified…

Abstract

Purpose

The purpose of this paper is to synthesise cyclohexanone formaldehyde resin (CFR)‐modified carbazole‐9‐carbonyl chloride (CzCl) via hydroxyl groups of CFR. This carbazole‐modified resin (Cz‐CFR) comonomer was characterised by common techniques such as UV, NMR, FTIR, fluorescence spectrophotometer, and scanning electron microscopy. The oxidative and electrochemical polymerisation of CzCl‐modified cyclohexanone formaldehyde resin (Cz‐CFR) were carried out.

Design/methodology/approach

Cz‐CFR comonomer was synthesised by the esterification reaction of CzCl and hydroxyl groups of CFR. Then, for the chemical polymerisation, ceric ammonium nitrate (CAN)/DMF solution was added to the comonomer/DMF solution. The precipitate was filtered, washed with chloroform and dried. For the electrochemical polymerisation, potentiodynamic electrodeposition of Cz‐CFR comonomer in dichloromethane on to Pt was carried out.

Findings

The concentration effect of CAN and Cz‐CFR on the conductivity, yield, solubility and Tg values of the polymers (P(Cz‐CFR)) were investigated. Spectrophotometric (UV‐visible, NMR), and cyclovoltammetric, polarisation curves, solid‐state conductivity and in situ spectroelectrochemical measurements were performed for the characterisation of homopolymer (polycarbazole (PCz)) and P (Cz‐CFR) films comparatively. The ionisation potentials (Ip), electron affinity (Ea), optical band gap (Eg), peak potentials (Ep), doping degree (y), and specific capacitance (Csp), of polymer films were calculated from the results of polarisation curves, cyclovoltammetry and electrochemical impedance spectroscopy.

Research limitations/implications

This paper focuses on obtaining a conductive polymer by using a fluorescence comonomer, which is an insulator.

Practical implications

This work provides technical information for the synthesis of fluorescence comonomer and conducting an alternative polymer.

Originality/value

The paper describes how a new Cz‐CFR comonomer was synthesised. This comonomer has a higher Tg value than CFR alone and also has fluorescence property. Cz‐CFR was polymerised by ceric salt and by electrochemical polymerisation. The band gap of the copolymer is not remarkably lower than polycarbazole.

Details

Pigment & Resin Technology, vol. 40 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 6 January 2012

Belkis Ustamehmetoğlu, Ahmet Akar, Nilgun Kizilcan and Eda Kelleboz

The purpose of this paper is to develop the soluble and processable conducting copolymers of carbazole (Cz), ethylcarbazole (ECz), N‐vinylcarbazole (NVCz) by oxidatively…

Abstract

Purpose

The purpose of this paper is to develop the soluble and processable conducting copolymers of carbazole (Cz), ethylcarbazole (ECz), N‐vinylcarbazole (NVCz) by oxidatively polymerising carbazoles by ceric ammonium nitrate (CAN) in the presence of methyl ethyl ketone formaldehyde resin (MEKF‐R); and to report the advantages of obtaining copolymer structure.

Design/methodology/approach

A new class of soluble and conductive P(Cz/MEKF‐R), P(NVCz/MEKF‐R) and P(ECz/MEKF‐R) copolymers were synthesised by the method of oxidative polymerisation with ceric ammonium nitrate. MEKF‐R, CAN and carbazole monomers (Cz, NVCz and ECz) were dissolved in acetonitrile separately. Then, the CAN solution was added dropwise into the mixture of MEKF‐R and Cz, NVCz or ECz solutions while stirring and a green powder was formed almost instantaneously. After one hour stirring at 25°C, the powder was filtered, washed with acetonitrile and dried at room temperature. A green coloured product was obtained. The colourless insulator copolymer present in this product was separated by selectively dissolving with toluene. The insoluble green copolymer was filtered off and dried at room temperature under vacuum. The products were characterised by FTIR, DSC thermograms, 1H‐NMR, four‐point probe conductivity and atomic absorption measurements.

Findings

The solubility and conductivity of the Cz/MEKF‐R copolymer P(Cz/MEKF‐R), the NVCz/MEKF‐R copolymer P(NVCz/MEKF‐R) and the ECz/MEKF‐R copolymer P(ECz/MEKF‐R) were regulated by the ratios of (Cz, NVCz, ECz)/CAN/MEKF‐R. By inclusion of the ketonic resin segments to the polycarbazole chains, thermally processable copolymers have been obtained with a melting point of about 80°C. FT‐IR results in different reaction time and the presence of metal in copolymers show together a complex between monomer‐metal and resin.

Research limitations/implications

This study focuses on obtaining conductive, soluble and processable copolymers. Since the ketonic resin is an insulator, in order to obtain both conductive and totally soluble polymer, successively regulating the ratios of (Cz, NVCz, ECz)/CAN/MEKF‐R is necessary.

Practical implications

This work provides technical information for the synthesis of conducting and totally soluble copolymer.

Originality/value

The conductive P(Cz/MEKF‐R), P(NVCz/MEKF‐R) and P(ECz/MEKF‐R) copolymers obtained by the method of oxidative polymerisation with ceric ammonium nitrate, which are totally soluble in DMF, could only be produced with this method and may increase the area of application of the carbazole polymers.

Article
Publication date: 5 July 2011

Belkis Ustamehmetoğlu, Pelin Yazıcı and Nilgun Kızılcan

The purpose of this paper is to obtain a conductive polymer by using a fluorescence comonomer which is an insulator. In this study, methyl ethyl ketone formaldehyde resin (MEKFR…

Abstract

Purpose

The purpose of this paper is to obtain a conductive polymer by using a fluorescence comonomer which is an insulator. In this study, methyl ethyl ketone formaldehyde resin (MEKFR) modified with carbazole‐9‐carbonyl chloride (CzCl) was synthesised via hydroxyl groups of MEKFR. Electrochemical polymerisation of Cz‐MEKFR comonomer was carried out potentiostatically and a green, conductive polymer P(Cz‐MEKFR) was obtained. The advantages of obtaining alternative structure of P(Cz‐MEKFR) to the random copolymer were reported.

Design/methodology/approach

Cz‐MEKFR comonomer was synthesised by the esterification reaction of CzCl and hydroxyl groups of MEKFR. Then, for the electrochemical polymerisation, potentiodynamic electrodeposition of Cz‐MEKFR comonomer in dichloromethane on to Pt was carried out. Electrochemical activities of polymers were tested by electrochemical methods (i.e. polarization curves and cyclovoltammetry). UV‐visible, NMR, polarization curves, cyclovoltammetric, solid‐state conductivity measurements and in situ spectroelectrochemical methods were performed for the characterization of polymers.

Findings

Carbazole‐9‐carbonyl chloride(CzCl) modified MEKFR was synthesised. This new carbazole‐modified resin (Cz‐MEKFR comonomer) has fluorescence property. The ionization potentials (Ip), electron affinity (Ea), optical band gap (Eg), peak potentials (Ep) and doping degree (y) of the polymers were calculated. Results were compared with the PCz homopolymer and the copolymer obtained from the mixture of MEKFR with carbazole P(Cz‐co‐MEKFR).

Research limitations/implications

This study focuses on obtaining a conductive polymer by using a fluorescence comonomer which is an insulator. In order to remove pyridine from comonomer, successively washing with several portions of dilute aqueous H2SO4, water‐saturated aqueous sodium hydrogen carbonate, and hot water is necessary.

Practical implications

This work provides technical information for the synthesis of fluorescence comonomer and conducting an alternative polymer.

Originality/value

A new Cz‐CFR comonomer was synthesised. This comonomer has a higher Tm value than MEKFR alone and also has fluorescence property. The band gap of the copolymer is not remarkably lower than polycarbazole. The oxidation potential of P(Cz‐MEKFR) was found to be higher than the PCz homopolymer and the solubility of copolymer is 30 per cent higher than homopolymer.

Details

Pigment & Resin Technology, vol. 40 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 7 June 2019

Grzegorz Tomaszewski, Jerzy Potencki, Grzegorz Błąd, Tadeusz Wałach, Grzegorz Gajór, Alena Pietrikova and Peter Lukacs

The purpose of this paper is to study the repeatability of path manufacturing in the drop on demand inkjet printing process and the influences of environmental and application…

Abstract

Purpose

The purpose of this paper is to study the repeatability of path manufacturing in the drop on demand inkjet printing process and the influences of environmental and application factors on path resistance.

Design/methodology/approach

Paths were printed as multiline paths in packets one-, two- and three-layer paths on polyimide substrates using nanoparticle silver ink. The sintering conditions were determined experimentally. The paths were subjected to climatic and shock exposures and to bending processes. The resistance, profile and width of the paths were measured and analyzed. The temperature distribution for electrically heated paths was measured to identify the defects.

Findings

This research shows the repeatability of printing processes and identifies the sources that cause diversification in path parameters after the whole technological process. The influence of shock, climatic and mechanical exposures on path electrical properties is indicated. An effective method for identifying defects thermally is shown.

Research limitations/implications

The research could have limited universality by arbitrarily use of substrate material, ink, printhead, process parameters and kind of sample exposures.

Practical implications

The research includes practically useful information about the width, thickness, defects and resistances and their changes during a typical application for a path printed with different technological parameters.

Originality/value

This research presents the results of original empirical research on problems concerning the manufacture of paths with uniform parameters and shows how path parameters will change under exposures that may occur in a typical application. The research combines both production and application aspects.

Details

Circuit World, vol. 45 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

1 – 4 of 4