Ali Durmus

Ali Durmus
Istanbul University-Cerrahpasa · Chemical Engineering

PhD
Research interests; (i) polymer physics, (ii) polymer processing and rheology, (iii) polymer blends and composites

About

76
Publications
22,515
Reads
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2,021
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Introduction
Dr. Durmus mainly works on polymer physics and polymer technology including thermoplastic composite and blends, polymer processing and rheology, structure-property relationships, viscoelasticity, crystallization kinetics and recently; functionalization and novel applications of thermoplastic elastomers such as self-healing compounds, shape-memory polymers, pressure sensitive adhesives for transdermal films, and utilization of specifically designed functional fillers in composite structures and engineering applications such as preparation of radar absorbing and/or EMI shielding composites, sensors, and gas seperation membranes etc.
Additional affiliations
August 2020 - present
Istanbul University-Cerrahpasa
Position
  • Professor (Full)
May 2018 - August 2020
Istanbul University-Cerrahpasa
Position
  • Professor (Associate)
October 2013 - May 2018
Istanbul University
Position
  • Professor (Associate)
Description
  • Polymer Physics (Undergrad.); Composite Materials (Undergrad.); Instrumental Analysis (Undergrad.); Rheology (Grad.); Polymer Processing and Rheology (Grad.)

Publications

Publications (76)
Article
In this study, effects of copolymer composition on the structural, thermal, and viscoelastic properties of segmented multi‐block polyamide elastomers (PEBAX® 3533, 5533, and 6333) and polyamide‐12 (PA12) were quantified by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry, and dynamic mechanical analysis (DMA) method...
Article
The aim of work is to highlight the evolution of physico-chemical properties of peroxide crosslinked polyethylene (XLPE) insulation material exposed to electrical aging. Specific analysis and characterization studies were carried out to determine the effect of electrical aging on different samples at micro and macro levels. Based on the analytical...
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This paper deals with the effects of ultraviolet (UV) light radiations on the properties of low-density polyethylene (LDPE) cable insulating materials. The aim is to evaluate changes in their physicochemical, electrical and mechanical properties after exposure to UV radiations. These changes were assessed by Fourier Attenuated Total Reflection Four...
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This study investigates effects of compositional variations and processing parameters such as ultrasonication time, carbon nanotube (CNT) content, and functionalization of CNT on the rheological, electrical, mechanical, and viscoelastic properties of epoxy-based composites filled with carbon nanomaterials. Expanded graphite (EG) was also used as a...
Article
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This study quantifies long-term physical properties of low density polyethylene (LDPE) cables insulations exposed to UV radiation and temperature as environmental constraints via both experimental measurements and mathematical modeling approach. For this purpose, tensile test and electrical breakdown test were carried out to determine elongation at...
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The technological, thermal, and antimicrobial properties of biocomposite films produced from polylactic acid (PLA) and thermally treated wood flour with in situ generated nanosilver particles (AgNPs) using a bio-reduction method. The extracts of fresh leaves of the phenolic-rich Oriental sweetgum (Liquidambar orientalis) tree were used as the reduc...
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Polylactide (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend nanocomposites including 3 wt% of cellulose nanocrystals (CNCs) were prepared by melt compounding method in a twin-screw extruder and an internal mixer. Blend nanocomposites were formulated by diluting three different masterbatches prepared by solution casting method that conta...
Article
In this study, thermoplastic based mixed matrix membranes (MMMs) were prepared by using cyclic olefin copolymer (COC) and two different metal organic frameworks (MOFs), HKUST-1 and MIL-53(Al) via solution mixing (SM) and melt processing (MP) methods. Structural and physical properties of COC, MOFs, and MMMs were characterized by SEM, XRD, TGA, and...
Article
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In this study, the effect of cellulose nanocrystals (CNCs) on the properties of polylactide (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends was investigated. Samples were prepared via (i) solution casting (SC) and (ii) combination of solution casting and melt mixing through twin-screw extruder (mTSE). Scanning electron microscopy images...
Article
Polymeric membranes, especially polyimide membranes, are widely preferred in gas separation processes due to their superior properties such as inherently high permeability, selectivity, and easy processing. Zeolitic imidazolate frames (ZIFs) are crystalline porous materials exhibiting some unique properties, such as tunable pore sizes, thermal and...
Article
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Cellulose nanocrystal (CNC)-reinforced poly(butylene adipate-co-terephthalate) (PBAT) nanocomposites with CNC contents of 1, 3, and 5 wt% were prepared through either solution casting or dilution of a PBAT/CNC masterbatch through melt mixing. The efficiency of these preparation approaches on CNC dispersion quality was examined using transmission el...
Article
The bead foaming behavior of ether- and an ester-based Tensor Processing Unit (TPU) resins were investigated in a lab-scale reactor using supercritical CO 2 as the blowing agent. The samples were saturated at various saturation temperatures and the effects of hard segment crystallization during the saturation on the foaming behavior of the TPU samp...
Article
Polylactide (PLA)/cellulose nanocrystal (CNC) nanocomposites with 1, 3, and 5 wt% CNC contents were prepared through (a) solution casting and (b) dilution of solution‐casted PLA/CNC masterbatch though melt mixing in a twin‐screw extruder. The effect of preparation method on the CNC dispersion quality and hence the final properties of the nanocompos...
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I am very happy to announce that the Non-Metallic Material Science (NMMS) which is an open access and multidisciplinary academic journal and a technical platform bringing out original research work and covering all aspects of non-metallic materials, has started its publication journey by the Bilingual Publishing Co., in 2019. The scope of the journ...
Article
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In this study, morphological features, dielectric properties, and microwave absorbing performances of thermoplastic polyurethane composite sheets prepared with solution mixing method by using different amounts and types of carbon fillers, carbon black (CB), graphite (G), carbon nanofiber (CNF), and multiwalled carbon nanotube (MWCNT) were investiga...
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Polyolefin blend type thermoplastic elastomers (TPEs) were prepared via melt blending method in a twin screw extruder by using isotactic polypropylene (i-PP), three different styrene-olefin triblock copolymers (SEBS-1 and SEBS-2 having a styrene content of 30 wt% and 60 wt%, respectively and SEEPS having a styrene content of 30 wt%) and paraffinic...
Article
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In this study, physical properties of high density polyethylene (HDPE) films, blended and reinforced with small amounts of liquid crystal polymer (LCP) and organoclay (org-clay), were investigated by employing different characterization tools such as XRD, SEM, DSC, rotational rheometer, DMA, and gas permeability measurements. Viscoelastic propertie...
Article
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Aim:: Incomplete polymerization of a resin material used for dental restoration affects the properties of the restoration. We evaluated the structural and mechanical properties of three different colored compomers cured with three different LED units to observe the characteristic changes occurring in different matches. Methods:: Polytetrafluoroe...
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In this study, melt-state rheological behavior and solid-state mechanical properties of polypropylene (PP)/wood fiber (WF) composites were investigated in detail depending on compositional variations such as (i) alkaline treatment on WFs, (ii) fiber size, (iii) WF content, and (iv) compatibilizer/WF ratio. Composite samples were prepared in a lab-s...
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In this study, polypropylene-based thermoplastic elastomer compounds (TPEs) were formulated by using isotactic polypropylene (i-PP), poly(styrene-b-ethylene/butylene-b-styrene) (SEBS), paraffinic oil and three different inorganic fillers; calcite, organo-clay, and halloysite. Structural, thermal, and rheological properties of TPEs were characterize...
Article
In this study, graphene oxide/zinc oxide (GO/ZnO) nanocomposite was prepared by the decoration of thermally expanded and chemically oxidized graphite oxide nanosheets with zinc oxide (ZnO) nanoparticles synthesized via two-step sol-gel deposition method and used as an effective photocatalyst for degradation of basic fuchsin (BF) dye. Structural pro...
Article
This study examined the dielectric properties of linear low density polyethylene (LLDPE)/organo-clay nanocomposites including the same amount of maleic anhydride grafted polyethylene (PE-g-MA) and oxidized polyethylene (OxPE) as compatibilizer at different frequencies (10-1-10+7 Hz) and temperatures (237-373 K). The dielectric constant of natural L...
Article
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In this study, cyclic olefin copolymer/poly(ethylene-co-vinyl acetate) 90/10, 80/20, and 70/30 blends were prepared by melt processing in a twin screw extruder equipped with a cast film haul-off unit to make films. Microstructural, rheological, mechanical, and viscoelastic properties of film samples were investigated by various tests performed in s...
Article
Full-text available
In this study, polyolefin blend type thermoplastic elastomer compounds were prepared via melt blending method in a twin screw extruder by using isotactic polypropylene (i-PP) as thermoplastic matrix, three different styrene-olefin triblock copolymers (SEBS-1 and SEBS-2 having styrene contents of 30 wt% and 60 wt%, respectively and SEEPS having a st...
Article
In this study, we quantified the thermal and solid-state mechanical and viscoelastic properties of isotactic polypropylene (i-PP) homopolymer and poly(propylene-1-butene) copolymer films having a 1-butene ratio of 8, 12, and 14 wt %, depending on the comonomer content. The uniaxial tensile creep and stress-relaxation behaviors of the samples were s...
Article
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Objective The main goal of this study was to compare the polymerization degree of bulk-fill giomer resin cured with three different light-curing units (LCUs): a polywave third-generation (Valo); a monowave (DemiUltra: DU); and a second-generation LED (Optima 10: Opt) LCUs by using structural and mechanical properties. Material and methods Giomer s...
Article
In this study, effect of processing method on the microstructure formation and related electrical conductivity and electromagnetic interference shielding effectiveness of carbon nanofiber (CNF) filled thermoplastic polyurethane (TPU) composites, prepared via three different processing techniques; (i) melt compounding (MC) in a twin screw extruder,...
Article
In this study, microstructural features and physical properties of thermoplastic poly-urethane (TPU)/organoclay nanocomposites films prepared via melt blending (MB) and solution mixing (SM) methods were investigated in detail. Amount of organoclay into the composition varied in the range of 2 and 8 wt%. Microstructural properties of samples were ch...
Article
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In this study, mixed-structure carbon–magnetite nanocomposites were prepared by decorating of carbon nanofiber (CNF) surfaces with magnetite (Fe3O4) nanoparticles synthesized via reflux method and characterized. The compositions of CNF–Fe3O4 nanocomposites were varied using different amounts of CNF into the Fe3O4 synthesis medium as 25/75, 50/50, a...
Article
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In this study, isotactic polypropylene (PP)/polyoxymethylene (POM) blend films, including of POM as minor phase in the range of 10-30 wt%, were prepared in a twin screw extruder equipped with a slit-die and cast film haul-off unit. It was found that the blend films showed characteristic immiscible matrix-droplet morphology. Short-term uniaxial tens...
Article
In this study, novel type carbon/ferrite nanocomposites were successfully prepared by decoration of graphene sheets with the magnetic strontium hexaferrite nanoparticles synthesized via the citrate sol-gel combustion method as microwave absorbing material. The microstructural features and physical properties of nanocomposites were characterized by...
Article
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The effect of wood-derived charcoal flour on the water resistance and mechanical properties of wood plastic composite (WPC) panels was investigated. The hot press molded WPC panels were produced from polypropylene (37 wt%) with maleic anhydride-grafted polypropylene (MAPP, 3 wt%) and different mixtures of wood flour and charcoal flour. The amount o...
Article
In this study, first, polyethyleneimine was acrylated and mixed with polyvinyl alcohol solution to prepare photo-crosslinked polyethyleneimine (PEI)-based nanofibers by utilizing ultraviolet and electrospinning technique at the same time. For CO2 permeability testing, same formulations were prepared by using solvent casting technique and exposed to...
Article
In this study, barium hexaferrite nanoparticles were synthesized via the citrate sol–gel combustion method in a reaction medium consisting of various forms of graphene nanosheet, such as expanded graphite, expanded graphite oxide, and reduced graphite oxide to prepare novel type graphene/hexaferrite nanocomposites as microwave-absorbing material. T...
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Full-text available
In this work, high density polyethylene (HDPE)/organo-clay (Cloisite® 15A) nanocomposites were prepared by melt processing using a commercially available oxidized polyethylene/oxidized (ethylene-co-vinyl acetate) copolymer blend (30:70 wt%) (AC® 645 supplied from Honeywell) as compatibilizer. Clay and compatibilizer amounts were varied to optimize...
Article
Melting and non-isothermal crystallization behaviors, oxidative induction time, and fire performance of the injection-molded wood flour-high density polyethylene (HDPE) composites (WPCs) incorporated with different levels (4, 8, or 12 wt %) of boron compounds [borax/boric acid (BX/BA) (0.5:0.5 wt %), zinc borate (ZB)] and phosphorus compounds [mono...
Article
Polyurethane nanocomposites are versatile engineering polymers with unique properties. In this study, nano hexagonal boron nitride containing thermoplastic polyurethane elastomers were prepared via melt blending and hot-pressing techniques. The nanocomposites were characterized using Fourier transform infrared, differential scanning calorimetry, th...
Article
Thermal, rheological, and physical properties of amorphous poly(ethylene terephthalate) (PET)/organoclay nanocomposite films which were successfully prepared with melt processing method using a PET/organoclay masterbatch were studied in detail. Structural and physical properties of the films were characterized by the UV–Vis spectroscopy, XRD and SE...
Article
In this study, effects of various types of functional polyolefin copolymers (FPOCs), poly(isobutylene-alt-maleic anhydride), poly(maleic anhydride-alt-1-octadecene) and poly(ethylene-graft-maleic anhydride), on the microstructure formation, interfacial interaction and physical properties of cyclic olefin copolymer (COC)/graphite composites were inv...
Article
In this study, morphological and rheological properties of cycloolefin copolymer (COC)/graphite composites prepared in a twin screw extruder by using various amounts of graphite (G) and expanded graphite (EG) were investigated in detail. Rheological behaviors of the samples were measured in a dynamic oscillatory rheometer in the melt state. Rheolog...
Article
In this study, structural, rheological and mechanical properties of cycloolefin copolymer/organoclay nanocomposite films were investigated in detail. A maleic anhydride grafted polyethylene was used as conventional compatibilizer. In a series of samples, poly(ethylene-co-1-octene) copolymer was also used as a secondary component in the sample formu...
Article
In this study, nonisothermal crystallization kinetics of glass fiber (GF) and clay‐type mineral (MN)‐reinforced polyamide‐6 (PA6) composites prepared in a twin screw extruder were investigated by differential scanning calorimetry method in the presence and absence of an organic nucleating agent (NA). Kinetic parameters for the nonisothermal melt‐cr...
Article
In this study, poly(butylene terephthalate) (PBT)/halloysite composites having various amounts of halloysite, as a one-dimensional (1D) nanotubular alumina-silicate filler, were prepared by melt processing in a twin screw extruder. Nonisothermal crystallization behaviors of the samples were studied by DSC and XRD methods. The effect of halloysite a...
Article
In this study, isothermal crystallization kinetics of polyamide 6 (PA6) composites reinforced with surface-treated glass fiber (GF) and natural, clay-type mineral (MN) were investigated by differential scanning calorimetry method in the presence and absence of a nucleating agent (NA). Microstructural features of the composites and interfacial inter...
Article
In this study, melt-crystallization behaviors of poly(butylene terephthalate) (PBT) composites including different types of inorganic fillers were investigated. Composite samples having 5 wt % of fillers were prepared by melt processing in a twin screw extruder using commercial grades of calcite (CA), halloysite (HL), and organo-montmorillonite (OM...
Article
Full-text available
In this work, structurally enhanced hydrogel nanocomposites based on 2-acrylamido-2 methyl propane sulfonic acid (AMPS)-acrylamide (AAM) copolymer with high hydrophilic group content were prepared by in-situ copolymerization by using different types of clay (montmorillonite, mica and halloysite). Nanocomposite hydrogels were characterized by Fourie...
Article
The paper is concerned with the formation of Layer-by-Layer (LbL) self-assembly of highly charged polyvinyl sulfate potassium salt (PVS) and polyallylamine hydrochloride (PAH) on Nafion membrane to obtain the multilayered composite membranes with both high proton conductivity and methanol blocking properties. Also, the influences of the salt additi...
Article
In this work, high density polyethylene (HDPE)/organo-clay (Cloisite® 15A) nanocomposites with different types of compatibilizer and having various clay amount and compatibilizer/clay weight ratio were prepared by melt blending in a batch, internal mixer. Poly(ethyleneco- metacrylic acid) Na+ salt, poly(ethylene-co-acrylic acid) and poly(ethylene-g...
Article
Full-text available
A series of highly proton conductive electrolyte membranes with improved methanol barrier properties are prepared from polyallylamine hydrochloride (PAH) and polystyrene sulfonic acid (PSS) including salt by Layer-by-Layer (LbL) method. The effects of added salt type (NaCl, MgCl2) and salt concentration (1.0M, 0.1M) on proton conductivity (σ) and m...
Article
In this study, effects of commercial additives such as antioxidant and stabilizer on the non-isothermal crystallization kinetics of isotactic polypropylene without nucleating agents were investigated by differential scanning calorimetry (DSC) method. Kinetic parameters by Osawa, Avrami and Liu-Mo models and apparent activation energy of the crystal...
Article
In this study, cold and melt crystallization behaviors of amorphous poly(ethylene terephthalate) (PET)/clay nanocomposites were investigated. Two nanocomposite samples with the same amount of inorganic content were prepared by melt processing using natural montmorillonite (Na-MMT) and organo-modified montmorillonite (org-MMT). Depending on the clay...
Article
The paper is concerned with the deposition of self-assembled polyelectrolyte multilayer on Nafion membrane by layer-by-layer (LbL) technique with lowered methanol cross-over for direct methanol fuel cell (DMFC) applications. The formation of self-assembled multilayered film on Nafion was characterized by UV–vis spectroscopy and it was found that th...
Article
In this study, mechanical properties of the linear low-density polyethylene (LLDPE)/ org-clay nanocomposites prepared by melt processing were investigated. Aspect ratio (A f) of the clay layers were estimated by using the Halpin-Tsai (H-T) micromechanical model based on the enhancement of the Young's modulus (E) with the clay loading (f). Strength...
Article
Novel type hydrogel-clay nanocomposites based on the acrylamide (AAm)- 2-acrylamido- 2-methylpropane sulfonic acid (AMPS) sodium salt and clay were synthesized via in situ copolymerization in aqueous solution. Samples were characterized by determining total basic group (TGB) content and swelling degree, XRD analysis, and FTIR spectroscopy. Effects...
Article
Acrylamide (AAm)-2-acrylamide-2-methylpropanesulfonic acid sodium salt (AMPSNa) hydrogel and AAm-AMPSNa/clay hydrogel nanocomposite having 10 w% clay was prepared by in situ copolymerization in aqueous solution in the presence of a crosslinking agent (N,N′-methylenebisacrylamide (NMBA)). Swelling properties and kinetics of the hydrogel samples were...
Article
Full-text available
Birçok uygarlığın doğduğu Anadolu topraklarındaki arkeolojik çalışmalarda, mineralli suların kullanımına ilişkin elde edilen bulgular zengin bir kaplıca tedavisi geleneğine işaret etmektedir. Batı Anadolu bölgesinde çok sayıda termomineralli suyun bulunuşu ve kaplıca merkezlerinde kullanılması kaynakların balneolojik yönden değerlendirilmesini gere...
Article
The nonisothermal crystallization kinetics of poly(ethylene terephthalate) (PET) copolymers modified with poly(lactic acid) (PLA) were investigated with differential scanning calorimetry, and a crystal morphology of the samples was observed with scanning electron microscopy. Waste PET (P100) obtained from postconsumer water bottles was modified wit...
Article
In this study, the use of low molecular weight oxidized polyethylenes (OxPE) with different molecular weight and acid number as a new type of compatibilizer in low density polyethylene (LLDPE)/org-clay nanocomposite preparation was examined. Nanocomposites having 5 phr (part per hundred) org-clay were prepared by melt processing. The effect of comp...
Article
In this study, linear low density polyethylene (LLDPE)/clay nanocomposites with various clay content were prepared by melt processing using two different compatibilizers, maleic anhydride grafted polyethylene (PE-g-MA) and oxidized polyethylene (OxPE). Effects of structure and physical properties of the compatibilizers on the clay dispersion and cl...
Article
In this study, thermal degradation of additive-free polypropylene powder over different type of zeolite catalysts was investigated. BEA, ZSM-5 and MOR with different surface areas, pore structures, acidities and Si/Al molar ratios were used as solid catalysts for degradation of polypropylene (PP). Degradation rate of the PP over zeolites was studie...
Article
In this study, various effects on the properties of the material, such as free-radical (FR) processes, oxygen induction time (OIT), melting temperature and melting heat are examined during several stages of the polyethylene (PE) pipe extrusion process. The spectra in the Electron Spin Resonance (ESR) are researched between 77–293 K and in a wide ra...
Article
Full-text available
In this work, high density polyethylene (HDPE)/organo-clay (Cloisite® 15A) nanocomposites were prepared by melt processing using a commercially available oxidized polyethylene/oxidized (ethylene-co-vinyl acetate) copolymer blend (30:70 wt%) (AC® 645 supplied from Honeywell) as compatibilizer. Clay and compatibilizer amounts were varied to optimize...

Projects

Projects (7)
Project
We aimed to evaluate the structural and mechanical properties of three different dual cured bulk fill resin composites by analyzing the degree of conversion, surface microhardness, compressive strength, and elastic modulus of the samples using various test methods.