Chemical Engineering / Kimya Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/14

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Author: search.filters.author.Tıhmınlıoğlu, FundaSubject: search.filters.subject.Mechanical properties

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 3
    Citation - Scopus: 4
    Microfluidic-Assisted Preparation of Nano and Microscale Chitosan Based 3d Composite Materials: Comparison With Conventional Methods
    (Wiley, 2022) Tıhmınlıoğlu, Funda; Değer, Sibel; Tamburacı, Sedef; Tıhmınlıoğlu, Funda; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Although nanofillers contribute to improved physical characteristics and biological functionalities of polymer-based biomaterials, their dispersion in polymer matrices is still a challenging issue in terms of obtaining consistency for the inherent properties. To tackle this problem, homogenization techniques are applied to disperse the nanofillers in such polymers, however, these methods can cause undesired changes especially in the rheological properties and the physical structure of the biopolymer matrices. Recently, as a novel homogenization technique, microfluidization has been used to homogenize polymer nanocomposites to minimize these limitations. In this study, two different nanocomposite structures as chitosan/montmorillonite (CS/MMT) and chitosan/polyhedral oligomeric silsesquioxane nanocages (CS/POSS) were homogenized with microfluidization and investigated in terms of physical alterations. Furthermore, the effect of microfluidizer technique on material characteristics was compared with conventional homogenization techniques, i.e., ultrasonic bath and sonication in terms of solution, nano – (e.g., hydrodynamic size, drug encapsulation) and macroscopic material characteristics (e.g., porosity, mechanical properties, swelling and thermal degradation). It was found that the microfluidizer homogenization improves the physical characteristics in both nano and macroscale materials: Nanospheres obtained from CS/MMT composites showed enhanced stability, uniform size distribution (<100 nm, PDI: [removed]50%) whereas 3D porous CS/POSS scaffolds showed improved structural uniformity (i.e., homogeneous and interconnected microstructure) and enhanced thermal and mechanical properties. The obtained results indicate that the microfluidizer homogenization ensures a successful nanofiller dispersion in polymer matrices, thereby improving the biomaterial characteristics impressively compared to the sonication methods.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 18
    Effect of Corn-Zein Coating on the Mechanical Properties of Polypropylene Packaging Films
    (John Wiley and Sons Inc., 2011) Tıhmınlıoğlu, Funda; Atik, İsa Doğan; Tıhmınlıoğlu, Funda; Özen, Fatma Banu; 03.02. Department of Chemical Engineering; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    In this study, a novel film structure of corn zein coated on polypropylene (PP) synthetic films for food packaging applications was developed, and the mechanical properties of the resulting coated film, as affected by the coating formulation, were investigated. Composite structures of PP films coated with corn zein were obtained through a simple solvent casting method. Different amounts of corn zein (5 and 15%) were dissolved in 70 and 95% aqueous ethanol solution at 50 C. Solutions of corn zein plasticized with poly(ethylene glycol) and glycerol (GLY) at various levels (20 and 50%) were applied on corona-discharge-treated PP. A statistical analysis based on full factorial design was performed to examine the influence of the coating formulation on the final properties of the corn-zein-coated PP films. A significant (p < 0.05) improvement in the coated film’s mechanical properties was observed compared to those of the uncoated PP. The effect of the plasticization of the coating solutions was also quite significant. In general, GLY provided better improvements in the mechanical properties of the corn-zein-coated PP films. The statistical analysis of the results showed that the corn-zein and plasticizer concentrations and plasticizer type used in the coating formulations were more effective parameters and had significant effects on the mechanical behavior of the coated PP films. In conclusion, corn-zein coatings could have potential as alternatives to conventional synthetic polymers used in composite multilayer structures for food packaging applications.
  • Article
    Citation - WoS: 64
    Citation - Scopus: 70
    Mechanical and Morphological Properties of Recycled High-Density Polyethylene, Filled With Calcium Carbonate and Fly Ash
    (John Wiley and Sons Inc., 2006) Atikler, Ulaş; Başalp, Dildare; Tıhmınlıoğlu, Funda; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    In this study, mechanical and morphological properties of composites made up of recycled high-density polyethylene (HDPE) filled with calcium carbonate and fly ash (FA) were studied. Interfacial interactions were modified to improve the filler compatibility and mechanical properties of the composites by surface treatment of the FA filler with 3-amino propyl triethoxy silane. The composites were prepared by using a Thermo Haake Rheomixer. Effect of filler loading and treatment of FA with silane coupling agent on mechanical and morphological properties were investigated and it was found that silane treatment indicated significant improvements on the mechanical properties of the HDPE-FA composites. The improvement with silane treatment of FA was also confirmed by applying the Pukanszky model. Scanning electron microscopy on the fracture surface of composites had given direct evidence of better interfacial adhesion via silane treatment.
  • Article
    Citation - WoS: 183
    Citation - Scopus: 190
    The Effect of Interfacial Interactions on the Mechanical Properties of Polypropylene/Natural Zeolite Composites
    (Elsevier Ltd., 2004) Metin, Dildare; Tıhmınlıoğlu, Funda; Balköse, Devrim; Ülkü, Semra; Tıhmınlıoğlu, Funda; Ülkü, Semra; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The effect of interfacial interactions on the mechanical properties of polypropylene (PP)/natural zeolite composites was investigated under dry and wet conditions. Interfacial interactions were modified to improve filler compatibility and mechanical properties of the composites by surface treatment of natural zeolite with a non-ionic surface modifier; 3 wt% polyethylene glycol (PEG) and three different types of silane coupling agents; 3-aminopropyltriethoxysilane (AMPTES), methyltriethoxysilane (MTES) and 3-mercaptopropyltrimethoxysilane (MPTMS), at four different concentrations (0.5-2 wt%). PP composites containing (2-6 wt%) zeolite were prepared by an extrusion technique. The tensile properties of the composites determined as a function of the filler loading and the concentration of the coupling agents were found to vary with surface treatment of zeolite. Silane treatment indicated significant improvements in the mechanical properties of the composites. According to the dry and wet tensile test results, the maximum improvement in the mechanical properties was obtained for the PP composites containing 1 wt% AMPTES treated zeolite. The improvement in the interfacial interaction was confirmed using a semi-empirical equation developed by Pukanszky. Good agreement was obtained between experimental data and the Pukanszky model prediction. Scanning electron microscopy studies also revealed better dispersion of silane treated filler particles in the PP matrix.