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Article
Publication date: 28 June 2013

Nilgün Kizilcan and Esin Ateş

The purpose of this paper was as follows. The in situ chemical oxidation (ICO) of vinyl aniline modified cyclohexanone formaldehyde resin (CFVAnR) in the presence of potassium…

Abstract

Purpose

The purpose of this paper was as follows. The in situ chemical oxidation (ICO) of vinyl aniline modified cyclohexanone formaldehyde resin (CFVAnR) in the presence of potassium persulphate salt (K2S2O8) was accomplished in dimethyl sulphoxide (DMSO) solutions at 35°C and 70°C. The chemical composition and structure of the oxidized CFVAnR were characterised by nuclear magnetic resonance (1H‐NMR) spectroscopy, Fourier transform infrared (FT‐IR) spectroscopy, DSC, TGA and SEM.

Design/methodology/approach

The reactive vinyl and amine groups of the cyclohexanone formaldehyde resin were reacted in the presence of potassium persulphate. CFVAn resin was dissolved in DMSO inside a round bottom flask immersed in a water bath thermostated at reaction temperature of 35°C and 70°C, respectively. Solution of K2S2O8 was prepared in DMSO and this was added into the resin solution.

Findings

It was shown that the vinyl groups in the resin were reacted easily with persulphate salt to obtain chain extended CFVAnR (CECFVAnR). The oxidised 4‐vinyl aniline modified cyclohexanone‐formaldehyde resin has solublity in organic solvents.

Research limitations/implications

The reaction mixture must be stirred continuously. Temperature should be controlled to prevent the thermal polymerisation of vinyl group and higher branching of amino groups. The persulphate ion (S2O82−) has a standard oxidation potential, but when activated by heat (40‐60°C). Furthermore, sulphate radical can react with water or hydroxide to produce hydroxyl radical (−OH). When persulphate is used for in situ chemical oxidation (ISCO) application at relatively low temperatures (e.g. <20°C), the oxidation reactions are usually less aggressive due to a slow generation rate of SO4.

Practical implications

This study provides technical information for the synthesis of chain extended resins. The modified resins contain vinyl groups. The chemical radical system has been used to polymerise these vinyl groups and resins with much higher molecular weight might be produced. The resins may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces of a coating.

Social implications

This resin will be used for the preparation of AB‐ and ABA‐type block copolymers. These block copolymers may exhibit different properties due to incorporation of ketonic resins into the block copolymer structure.

Originality/value

Chain extended CFVAnR (CECFVAnR) was synthesised by one step reduction‐oxidation reaction, at 35°C (CECFVAnR1) and 70°C (CECFVAnR2) in the presence of potassium persulphate salt. These soluble resins may overcome difficulties in the applications of polymers and open new application areas. Therefore, the chain extended vinyl aniline modified resin may find a number of new application areas as well as existing UV curable resin and polymer applications.

Details

Pigment & Resin Technology, vol. 42 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 2 March 2015

Esin Ateş, Nilgün Kizilcan and Merve İstif

The purpose of this paper is to synthesise an electro-active monomer containing ketonic resins and then to investigate the redox reaction between Fe+3 and bound thiophene in…

Abstract

Purpose

The purpose of this paper is to synthesise an electro-active monomer containing ketonic resins and then to investigate the redox reaction between Fe+3 and bound thiophene in comonomer. First, thiophene-functionalised ketonic resins were synthesised by esterification reaction of thiophene-2-carbonyl chloride (ThCCl) and hydroxyl groups of cyclohexanone formaldehyde resin (CFR). Thiophene-containing cyclohexanone formaldehyde resin (Th-CFR) was then polymerised by ferric salt. The structures of the specimens were characterised by means of Fourier transform infrared and Proton – Nuclear Magnetic Resonanse (1H-NMR) spectroscopy. Thermal properties of the samples were determined with differential scanning calorimeter. Molecular weights of the specimens were determined by gel permeation chromatography. The obtained samples were also characterised morphologically by scanning electron microscope.

Design/methodology/approach

Synthesis of Th-CFR comonomers by a combination of condensation polymerization and chemical oxidation polymerisation processes is described. First, Th-CFR units were prepared by direct condensation reaction of thiophene-2-carbonyl chloride (ThCCl) and hydroxyl groups of CFR. Then, the chemical oxidation (CO) of Th-CFR in the presence of anhydrous iron (III) chloride salt (FeCl3) was performed in chloroform (CHCl3)/acetonitrile mixture solutions at room temperature.

Findings

The important structural factor determined quantitatively for Th-CFR is the CFR/ThCCl ratio after reaction. The effect of the mole ratio effect of ThCCl and ketonic resin on the solubility, molecular weight, Tm and Tg values of the comonomers (Th-CFRs) were investigated.

Research limitations/implications

The ferric ion (Fe+3) has a standard oxidation potential. Furthermore, FeCl3 can react with thiophene to produce a cation radical. FeCl3 cannot react with hydroxyl groups of ketonic resins. When ferric is used for in situ chemical oxidation application at relatively low temperatures (e.g. < 20°C), the oxidation reactions are usually less aggressive.

Practical implications

This work provides technical information for the synthesis of conducting block copolymer and for the synthesis of chain-extended resins. The modified resins contain electro-active monomer as thiophene. The chemical oxidation system has been used to polymerise these thiophene groups and resins with much higher molecular weight might be produced. These resins may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces of a coating.

Social implications

This will be used for the preparation of AB- and ABA-type block copolymers. These block copolymers may exhibit different properties due to incorporation of monomer into the block copolymer structure.

Originality/value

Novel Th-CFR comonomers were synthesised. These comonomers have higher glass transition temperature (Tg) and melting temperature (Tm) value than CFR alone. The chemical oxidation system has been used to polymerise these thiophene-functionalised ketonic resins.

Details

Pigment & Resin Technology, vol. 44 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 30 August 2013

Esin Ateş, Nurseli Uyanık and Nilgün Kızılcan

The purpose of the research was as follows. In situ modified urea formaldehyde resins were prepared from clay (montmorillonite) and organoclay in the presence of base catalyst…

Abstract

Purpose

The purpose of the research was as follows. In situ modified urea formaldehyde resins were prepared from clay (montmorillonite) and organoclay in the presence of base catalyst. Different clay contents (1 wt%, 3 wt%, 6 wt%) were used to produce clay modified nanocomposite resins. These nanocomposites were characterized with FT‐IR, XRD as structural analysis and DSC as thermal analysis and their hardness was evaluated as mechanical analysis. The thermal results was compatible with hardness measurements and showed that using clay/organoclay added resin as a surface coating material provides significant improvement.

Design/methodology/approach

During synthesis of the resin, modification was carried out using urea/formaldehyde with molar ratio of 1/1.6, under basic medium with pH=10 and with temperature of 70°C by loading pristine and organomodified layered silicates.

Findings

X‐ray diffraction (XRD) results indicate that the interlayer space of pristine clay was increased significantly by one step, seeing that one step processes are crucial for industrial applications.

Research limitations/implications

The reaction mixture must be stirred continuously. Temperature should be controlled in order to prevent the thermal curing of urea formaldehyde resin.

Practical implications

This study provides technical information for the synthesis of nanocomposite resins. The clay or organoclay modified resins may also promote the adhesive strength of coating and also inhibit corrosion effects to metal surfaces of the coated area.

Social implications

This resin will be used for the coating material.

Originality/value

As Tg‐Tm region of some nanocomposites is enhanced, and by assessing the results of hardness measurements, it is concluded that these samples have further improved mechanical properties as a coating material than urea formaldehyde resin has.

Details

Pigment & Resin Technology, vol. 42 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 29 June 2012

Esin Ateş and Nilgün Kızılcan

The purpose of this paper is to investigate in situ modification of cyclohexanone‐formaldehyde resins (CFR) by 4‐vinyl aniline (Van). The roles of the reaction temperature, the…

Abstract

Purpose

The purpose of this paper is to investigate in situ modification of cyclohexanone‐formaldehyde resins (CFR) by 4‐vinyl aniline (Van). The roles of the reaction temperature, the conductivity, thermal properties, and molecular weight of the product were investigated. CFR was in situ modified with VAn in the presence of sodium hydroxide. Ketonic resin‐bound 4‐vinyl aniline was synthesised with a one‐step method of in situ modification of ketonic resin. The roles of the reaction temperature and the conductivity of the product were investigated.

Design/methodology/approach

Ketone, formalin (37% aqueous solution), vinyl aniline were mixed and then 20% aqueous NaOH solution was added to produce the resin. The solubility, molecular weight and thermal properties of the products were investigated.

Findings

The 4‐vinyl aniline modified cyclohexanone‐formaldehyde resins were found to have conductivity values of 10−4 and 10−2 S/cm and may be considered as conductive ketonic resin. Soluble and processable conductive ketonic resins were developed.

Research limitations/implications

The reaction mixture of CFR must be stirred continuously at low temperature. Subsequently, 37% formalin was added dropwise in equal portions while refluxing. Temperature should be controlled to prevent the thermal polymerisation of vinyl group and higher branching of amino groups. The amount of vinyl aniline used in reaction mixture is limited since the formed resin may become insoluble in common organic solvents.

Practical implications

This study provides technical information for the synthesis of conducting resins. The modified resins contain vinyl groups. The chemical redox or radical system can be used to polymerise these vinyl groups and resins with much higher molecular weight may be produced. The resins may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces of a coating.

Originality/value

Vinyl aniline modified cyclohexanone formaldehyde resins have been synthesised in the presence of a basice catalyst. These soluble and conductive resins may overcome difficulties in the applications of conducting polymers and open new application areas. Therefore, the vinyl aniline modified resin may find a number of new application areas, as well as existing conducting resin and polymer applications.

Details

Pigment & Resin Technology, vol. 41 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 1 March 2012

Hilal Aycı and Esin Boyacıoğlu

If regionalism is defined as designing responsibly in reaction to a local context, then critical regionalism can be defined as doing so without denying the universally…

Abstract

If regionalism is defined as designing responsibly in reaction to a local context, then critical regionalism can be defined as doing so without denying the universally enlightening content of the modernist project. Armed with this definition, this article attempts to analyze two houses by architect Han Tümertekin that are set in a rural context in a very small Aegean village in Turkey. The aim of the paper is to explore the extent to which these two buildings embrace the tenets of critical regionalism and to understand the local relevance as well as international esteem of the buildings.

Details

Open House International, vol. 37 no. 1
Type: Research Article
ISSN: 0168-2601

Keywords

Article
Publication date: 1 December 2016

Serpil Özker and Umut Tuğlu Karsli

Externalization that became prominent in 1980s with the globalization brought along dramatic changes in social and spatial areas. The social, cultural and economic events that…

Abstract

Externalization that became prominent in 1980s with the globalization brought along dramatic changes in social and spatial areas. The social, cultural and economic events that took place on an international level thanks to globalization made the impact of change felt which was reflected on the urban space and, therefore, on the house, resulting in an increase in the importance of the residential sector. Externalization and developed economic structure enabled more investments into houses which introduced a concept of housing populated in urban fringes starting from the city centers. The housing concept which was shaped by the impacts of the urban transformation after 1980 turned into a new emerging lifestyle in Istanbul in 2000s. Accordingly, the study aims to establish the position of housing in Istanbul and new meanings formed by the socio-cultural changes. In this sense, housing before and after 1980, globalization, gentrification, urban transformation, spatial segregation, socio-economic and cultural aspects were discussed based on the structural benchmarks, and 4 different housing forms, namely the “Loft”, “Residence”, “Terraced House”, and “Gated Communities”, with individual structural examples. This study, thus, aims to question the form of tenancy of these houses created through varying concepts and concerns today. The results obtained showed that the housing as an indicator of cultural life in Istanbul has turned into a lifestyle that is shaped by similar aspects and commercial concern, despite different approaches or production forms, eliminating the traces of the cultural life of the society.

Details

Open House International, vol. 41 no. 4
Type: Research Article
ISSN: 0168-2601

Keywords

Book part
Publication date: 29 May 2024

Jingxian Wang

This research aims at explaining the phenomenon of the “black children” (heihaizi), a very little-known generation who lived with concealment under the one-child policy in China…

Abstract

This research aims at explaining the phenomenon of the “black children” (heihaizi), a very little-known generation who lived with concealment under the one-child policy in China. The one-child policy was officially introduced to nationwide at the end of 1979 by permitting per couple to have one child only, later modified to a second child allowed if the first was a girl in rural China in 1984. It was officially replaced by a nation-wide two-child policy and most existing research focused on the parents’ sufferings and policy changes. The term “black children” has been mainly used to describe their absence from their family hukou registration and education. However, this research aims at expanding the meaning of being “black” to explain the children who were concealed more than at the level of family formal registration, but also physical freedom and emotional bond. What we do not yet know are the details of their lived experiences from a day-to-day base: where did they live? How were they raised up? Who were involved? Who benefited from it and who did not? In this way, this research challenges the existing scholarship on the one-child policy and repositions the “black children” as primary victims, and reveals the family as a key figure in co-producing their diminished status with the support of state power. It is very important to understand these children’s loss of citizenship and human freedom from the inside of the family because they were concealed in so many ways away from public view and interventions. This research focuses on illustrating how their lack of access to continued, stabilized, and reciprocally recognized family interactions framed their very idea of self-worth and identity.

Details

More than Just a ‘Home’: Understanding the Living Spaces of Families
Type: Book
ISBN: 978-1-83797-652-2

Keywords

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