Nilgün Kızılcan - Academia.edu (original) (raw)

Papers by Nilgün Kızılcan

Pigment & Resin Technology, Sep 1, 2006

PurposeProposes to examine acceleration of photo‐oxidative degradation of high‐density polyethyle... more PurposeProposes to examine acceleration of photo‐oxidative degradation of high‐density polyethylene (HDPE) by using photosensitive acetophenone‐formaldehyde resin (AFR).Design/methodology/approachDegradation of HDPE by UV light was investigated in the presence of photosensitive AFR on natural weathering. The experiments were done at constant temperatures (40, 65 and 90°C). The results were determined by FT‐IR spectrophotometric and viscometric methods. Measurement of the rate of formation of carbonyl groups on the FT‐IR showed the evidence of degradation. The carbonyl indices of photo‐oxidation of HDPE with/without AFR were determined by FT‐IR spectroscopy. The molecular weights of the samples (Mη values) were measured by viscometry.FindingsThe amount of carbonyl present in the AFR containing HDPE samples and the changes in their molecular weights were found to depend on the irradiation period, temperature and amount of AFR in the mixture. The improvements in UV performance have been observed by using 1 per cent photosensitive AFR in the mixture. Photo‐oxidative degradation also appeared to be accelerated by heat.Research limitations/implicationsThis study can be focused on using photosensitive resins for the polymer degradations just as powder mixture, but the HDPE sample used did not contain antioxidants. From this point of view, commercial HDPE and AFR must be mixed as a film‐former and the AFR concentration will be higher than those of this work.Practical implicationsThis work provides technical information for the application of photosensitive resins for easy degradation of HDPE packaging materials.Originality/valueThe method in which a photosensitive resin is used in the polymer degradation may be a reference for other relevant studies.

Polysulfone (PSU) is a specialty engineering polymer having various industrial applicat... more Polysulfone (PSU) is a specialty engineering polymer having various industrial applications. PSU is especially used in waste water treatment membranes due to its good mechanical properties, structural and chemical stability. But it is a hydrophobic material and therefore its surface aim to pollute easily. In order to resolve this problem and extend the properties of membrane, PSU surface is rendered hydrophilic by addition of the sepiolite nanofibers. Sepiolite is one of the natural clays, which is a hydrate magnesium silicate fiber, also one of the well known layered clays of the montmorillonites where has several unique channels and pores within. It has also moisture durability, strength and low price. Sepiolite channels give great capacity of absorption and good surface properties. In this study, nanocomposites of commercial PSU and Sepiolite were prep...

This work presents synthesis of α,ω-dithienyl terminated poly(ethylene glycol) (PEGTh) ... more This work presents synthesis of α,ω-dithienyl terminated poly(ethylene glycol) (PEGTh) capable for further chain extension by either chemical or electrochemical polymeriztion. PEGTh was characterized by FTIR and 1H-NMR. Further copolymerization of PEGTh and pyrrole (Py) was performed by chemical oxidative polymerization using ceric (IV) salt as an oxidant (PPy-PEGTh). PEG without end group modification was used directly to prepare copolymers with Py by Ce (IV) salt (PPy-PEG). Block copolymers with mole ratio of pyrrole to PEGTh (PEG) 50:1 and 10:1 were synthesized. The electrical conductivities of copolymers PPy-PEGTh and PPy-PEG were determined by four point probe technique. Influence of the synthetic route and content of the insulating segment on conductivity and yield of the copolymers were investigated.

This study presents synthesis of novel block copolymers of thienyl end capped ethoxylat... more This study presents synthesis of novel block copolymers of thienyl end capped ethoxylated nonyl phenol and pyrrole via chemical oxidative polymerization. Ethoxylated nonyl phenol (ENP) was reacted with 2-thiophenecarbonyl chloride in order to synthesize a macromonomer containing thienyl end-group (ENPThC). Then copolymers of ENP-ThC and pyrrole were synthesized by chemical oxidative polymerization using iron (III) chloride as an oxidant. ENP-ThC served both as a macromonomer and an emulsifier for pyrrole with poor solubility in water. The synthesized block copolymers (ENP-ThC-b-PPy) were characterized by spectroscopic analysis and the electrical conductivities were investigated with 4-point probe technique.

Commercially available poly(acrylonitrile-co-vinyl acetate) P(AN-VA) or poly(acrylonitrile-co-met... more Commercially available poly(acrylonitrile-co-vinyl acetate) P(AN-VA) or poly(acrylonitrile-co-methyl acrylate) P(AN-MA) are not satisfactory to meet the demand in flame and fire-resistance. In this work, vinylphosphonic acid is used during polymerization of acrylonitrile, vinyl acetate, methacrylic acid to produce fire-retardant polymers. These phosphorus containing polymers are successfully spun in the form of nanofibers. Properties such as water absorption of polymers are also determined and compared with commercial polymers.

In situ modified cyclohexanone-formaldehyde resins were prepared by addition of alendro... more In situ modified cyclohexanone-formaldehyde resins were prepared by addition of alendronic acid during resin preparation. Clay nanocomposites in ketonic resins were achieved by adding clay into the flask at the beginning of the resin preparation. The prepared resins were used for the synthesis of fire resistant polyurethanes foam. Both phosphorous containing modifier compound alendronic acid and nanoclay increases fire resistance of the cyclohexanone-formaldehyde resin thus polyurethane produced from these resins. The effect of the concentrations of alendronic acid and clay on the fire resistance and physical properties of polyurethanes was studied.

Open Chemistry, 2021

Thermoplastic elastomer foams based on styrene–ethylene–butylene–styrene (SEBS)/polypropylene (PP... more Thermoplastic elastomer foams based on styrene–ethylene–butylene–styrene (SEBS)/polypropylene (PP) were produced by using different processing techniques such as extrusion and injection molding to achieve optimized mechanical and thermal properties in terms of strength, elongation, and damping capability. Foaming is a method of introducing gas-filled cells into the material and it is considered an effective way to meet the requirements for higher impact resistance with low density and relatively low hardness. In this study, microspheres were used as a foaming agent and were introduced to the system by using an injection molding machine. They were used in different percentages and ranged from 1 and 3%. They decrease the density of the product thereby lowering the weight and cost. Besides improving damping abilities and decreasing the density, inorganic fillers such as talc, silica, and calcium carbonate were used to increase the mechanical strength, and their effectivity was also inv...

Open Chemistry, 2021

In many plastic applications, improvement of the flame retardancy is a very significant topic. Po... more In many plastic applications, improvement of the flame retardancy is a very significant topic. Polypropylene (PP) is used in many applications such as housing industry due to its cost performance efficiency. Enhancement of flame retardancy properties of PP is necessary in many applications. In this study, the investigation focuses on the synergistic effect of mica mineral and IFR in enhancing the flame retardancy properties of PP in order to achieve cost competitive solution, so as to provide that different/various ratios of IFR and mica mineral were added into PP to compose 30 wt% of the total mass of the polymeric compounds. The synergistic effect of mica mineral with IFR in PP was investigated by limiting oxygen index (LOI), glow wire test (GWT), UL-94 test, thermal gravimetric analyses (TGA), and mechanical tests. The results from LOI, UL 94, and GWT tests indicated that mica added to PP/IFR compound has a synergistic flame retardancy effects with the IFR system. When the conten...

Procedia - Social and Behavioral Sciences, 2015

Polysulfone (PSU) is an amorphous engineering polymer with extraordinary chemical, thermal and me... more Polysulfone (PSU) is an amorphous engineering polymer with extraordinary chemical, thermal and mechanical properties. These properties might be listed as thermal stability, mechanical strength, high rigidity, stiffness, excellent resistance to hydrolysis, and acids and bases, resistance to creep, oxidative resistance and an extensive operative range of temperature and pH. Owing to these properties, polysulfones are used in the fields of materials science, biology and polymer science and have been the basis of numerous applications.. Up to this point, PSU membranes are prepared for the applications such as filtration, hemodialysis, bioartificial organs, gas separation, water purification systems, and fuel cells, etc. Sepiolite is a natural clay mineral. It is a member of layered silicates, especially it is a magnesium hydrosilicate. Its unique properties of high surface area, fibrous structure, porosity, crystal morphology and composition, surface activity, production of stable suspensions of high viscosity at low concentrations leads to many applications. In this work, composites of PSU and sepiolite were prepared by in situ polymerization technique. Sepiolite was utilized as both raw material and enriched with minerals (Ag, Cu). Synthesized composites were characterized by FTIR, NMR and XRD measurements and they are going to be used as membrane fabrication.

Procedia - Social and Behavioral Sciences, 2015

This study presents synthesis of novel block copolymers of thienyl end capped ethoxylated nonyl p... more This study presents synthesis of novel block copolymers of thienyl end capped ethoxylated nonyl phenol and polypyrrole with silver nanoparticles via chemical oxidative polymerization by iron (III) chloride. Ethoxylated nonyl phenol (ENP) was reacted with 2-thiophenecarbonyl chloride (ThCCl) in order to synthesize a macromonomer containing thienyl end-group (ENP-ThC). Then copolymers of ENP-ThC and pyrrole were synthesized by chemical oxidative polymerization using iron (III) chloride as an oxidant. During this reaction, silver nitrate (AgNO 3) solution was added in order to increase its conductivity and to give the copolymer anti-microbial property. The synthesized block copolymers (ENP-ThC-b-PPy) with silver nanoparticles were characterized by spectroscopic analysis and the electrical conductivities were investigated with 4-point probe technique. The obtained samples were also characterized morphologically by Scanning Electron Microscope (SEM).

Procedia - Social and Behavioral Sciences, 2015

This study presents synthesis of novel block copolymers of thienyl end capped polydimethylsiloxan... more This study presents synthesis of novel block copolymers of thienyl end capped polydimethylsiloxane and polypyrrole via chemical oxidative polymerization by iron (III) chloride. Mono hydroxy terminated poly (dimethylsiloxane) (MH.PDMS) was reacted with 2-thiophenecarbonyl chloride (ThCCl) in order to synthesize a polymer containing thienyl end-group (PDMS-ThC). Then copolymers of PDMS-ThC and pyrrole were synthesized by chemical oxidative polymerization using iron (III) chloride as an oxidant. The synthesized block copolymers (PDMS-ThC-b-PPy) were characterized by spectroscopic analysis and the electrical conductivities were investigated with 4-point probe technique. The obtained samples were also characterized morphologically by Scanning Electron Microscope (SEM).

Procedia - Social and Behavioral Sciences, 2015

In this study, in situ modified phenol formaldehyde resins were prepared from clay (sepiolite) in... more In this study, in situ modified phenol formaldehyde resins were prepared from clay (sepiolite) in the presence of base catalyst. Different clay contents (3 wt%, 5wt%, 8 wt%, 10 wt%, 15wt%, 20wt%, 30wt% and 50 wt%) were used to produce sepiolite modified resol nanocomposite resins (SEP-PFNCRs). SEP-PFNCRs were partially cured by heat and the effects of the curing process and the clay content in the resol resin were determined on the spectroscopic, thermal, and microscopic properties of the final products. The structures of the specimens were characterized by means of Fourier Transform Infrared (FTIR-ATR) spectroscopy. Thermal properties of the samples were determined with Thermogravimetric Analyzer (TGA). The dispersion of sepiolite in the resol nanocomposites were examined by X-ray Diffraction (XRD). The obtained samples were also characterized morphologically by Scanning Electron Microscope (SEM).

Pigment & Resin Technology, 2006

Pigment & Resin Technology, 2011

Purpose – The purpose of this paper is to synthesise cyclohexanone formaldehyde resin (CFR)-modif... more 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.

International Journal of Electrochemistry, 2011

Effect of some newly synthesized modified ketonic resins on corrosion inhibition of stainless ste... more Effect of some newly synthesized modified ketonic resins on corrosion inhibition of stainless steel (SS) and copper (Cu) was investigated in acidic medium. Carboxyl, hydroxyl, and carbonyl functionalized resins have been coated on metal electrode as a thin film by dipping method. Corrosion characteristics of coating on SS (304 L) and Cu were investigated by polarization, open-circuit, and impedance measurement. These measurements performed at different time and the stability of polymeric coating were tested with time in acidic medium. The resin coating was able to protect both the SS and copper.

Progress in Organic Coatings, 2013

In this study natural iron sulfide (FeS 2) surface was coated by films of poly(N-vinylcarbazole) ... more In this study natural iron sulfide (FeS 2) surface was coated by films of poly(N-vinylcarbazole) (PNVCz), poly(N-vinylcarbazole methylethylketoneformaldehyde resin) (P[NVCz-MEKF-R]), carbazole methylethylketone formaldehyde resin (Cz-MEKFR) and poly(carbazole methyl ethylketone formaldehyde resin) (P[Cz-MEKFR]). The corrosion, photocorrosion, and photoactivity characteristics of coated electrodes were investigated in potassium iodide/iodide (KI/I 2) redox electrolyte. The inhibition effect and photoactivity of Cz-MEKF-R, P[Cz-MEKF-R] P[NVCz-MEKFR] and PNVCz homopolymer coatings were compared. Coating performance was tested by polarization and electrochemical impedance (EIS) measurements. The photopotential and photocurrent values of bare and coated pyrite electrodes were obtained under illuminated conditions. The inhibition efficiencies were calculated from corrosion currents obtained by Tafel extrapolation from polarization curves.

Surface Coatings International Part B: Coatings Transactions, 2001

ABSTRACT Summaries A new generation of a series of five-block copolymers from acetophenone-formal... more ABSTRACT Summaries A new generation of a series of five-block copolymers from acetophenone-formaldehyde resins (AFR), poly(dimethyl siloxane) (PDMS), and poly(vinyl pyrrolidinone) (PVP) or poly(styrene) (PS) were synthesised to modify the compatibilities and surface properties of the block copolymers. For this purpose, PDMS-AFR-PDMS copolymers, which had different molecular weights and different AFR contents, were prepared first. These three-block copolymers were made diradicalic macroinitiators by a stepwise procedure. Vinyl pyrrolidinone and styrene were polymerised by using these diradicalic macroinitiators to prepare five-block copolymers. Intermediates and copolymers were characterised by physicochemical methods, FTIR and 1 H-NMR spectra. The molecular weights of block copolymers were measured by viscometry and by GPC. The solubility and thermal properties of copolymers and contact angles of block copolymeric films were measured. The overall results indicated that the chain-extended ketonic resins, even in the middle block, affect the characteristics of PDMS containing PVP or PS-block copolymers.

Pigment & Resin Technology, Sep 1, 2006

Open Chemistry, 2021

Procedia - Social and Behavioral Sciences, 2015

Pigment & Resin Technology, 2006

Pigment & Resin Technology, 2011

International Journal of Electrochemistry, 2011

Progress in Organic Coatings, 2013

Surface Coatings International Part B: Coatings Transactions, 2001