Synthesis and characterization of polystyrene clay nanocomposites

Özden, Gülsüm
This study was undertaken to prepare polystyrene (PS)/montmorillonite (MMT) nanocomposites by different methods, including melt intercalation, in-situ polymerization and masterbatch methods. The in-situ polymerization method consisted of dispersing the styrene monomer into the galleries of MMT followed by subsequent polymerization. The PS/MMT nanocomposites formed by melt intercalation method were prepared on a twin-screw extruder. The masterbatch method was in fact a two-step process. As the first step, a high clay content composite of polystyrene (masterbatch) was prepared by in-situ polymerization, and then the prepared masterbatch was diluted to desired compositions with commercial polystyrene in a twin-screw extruder.The structural, thermal and mechanical properties of the nanocomposites were examined. X-Ray diffraction (XRD) analysis showed that the d-spacing of the in-situ formed nanocomposites containing 0.73 and 1.6 wt. %organoclay increased from 32.9 ? to 36.3 and 36.8 ? respectively, indicating intercalation while the dspacing of the other prepared materials remained nearly unchanged compared to pure organoclay. At low clay content, (<1 wt.%), in-situ formed nanocomposites showed the best improvement in mechanical properties including tensile, flexural, impact strength and Young̕s modulus. In all the three methods, the addition of organoclay increased the Young̕s modulus compared to neat resin, but the maximum improvement was 88.5 %, obtained at 0.73 wt. % organoclay in the in-situ formed material. In-situ polymerization method did not prove to be efficient at high clay loadings in terms of mechanical properties. At high clay loadings, the effects of the three methods on promoting mechanical properties were not significantly different from each other. The glass transition temperature increased from 105.5 oC in the pure polystyrene to 108.4 oC in the in-situ


Synthesis and Stimuli-Responsive Properties of Metallo-Supramolecular Phosphazene Polymers Based on Terpyridine Metal Complexes
In this study, terpyridine functionalized phosphazene based metallo-supramolecular polymers were synthesized by three step reaction method. In the first step, 4 '-(4-aminophenyl)-2,2 ':6 ',2 ''-terpyridine was synthesized with p-nitro benzaldehyde and 2-acetylpyridine. Then, the monomer containing six terpyridine (TPY) units attached to the phosphazene was prepared from 4 '-(4-aminophenyl)-2,2 ':6 ',2 ''-terpyridine and hexachlorocyclotriphosphazene by a condensation reaction. Finally, metallo-supramolecula...
Synthesis of conducting block copolymers and their use in the immobilization of invertase and polyphenol oxidase enzyme
Kıralp, Senem; Kıralp, Senem; Department of Chemistry (2004)
A new thiophene derivative containing menthyl group (MM) was synthesized and polymerized via chemical and electrochemical methods. Polymers obtained and MM itself were used to synthesize copolymers with pyrrole under conditions of constant potential electrolysis. Cyclic Voltammetry, thermal analysis and scanning electron microscopy analyses were performed for the characterization of samples. Immobilization of invertase and polyphenol oxidase enzymes was performed in the matrices obtained via copolymerizatio...
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Tolga, Aslı; Yılmazer, Ülkü; Department of Chemical Engineering (2005)
In this study, the effects of glycol type, organoclay type and concentration on the final properties of nanocomposites based on recycled poly(ethylene terephthalate) was investigated. For this purpose, first recycled PET was glycolysed and after that unsaturated polyester-montmorillonite nanocomposites were synthesized by using three different types of glycols (i.e. ethylene glycol (EG), propylene glycol (PG) and diethylene glycol (DEG)). As the first step, all the compositions were prepared by Cloisite 30B...
Preparation and characterization of thermally stable organoclays and their use in polymer based nanocomposites
Abdallah, Wissam; Yılmazer, Ülkü; Department of Chemical Engineering (2010)
The present study was aimed at exploring the purification and modification of montmorillonite rich Turkish bentonites by organic salts and their subsequent effects on the morphology (X-diffractometry, transmission electron microscopy, scanning electron microscopy), melt flow index, mechanical (Tensile, Impact) and especially thermal stability (thermal gravimetric analysis, differential scanning calorimetry) properties of polymer/organoclay nanocomposites with and without an elastomeric compatibilizer. The b...
Production and characterization of nanofibers from polycaprolactam and ethylene-butyl acrylate-maleic anhydride terpolymer mixture
Biber, Erkan; Gündüz, Güngör; Department of Polymer Science and Technology (2010)
The impact strength of Nylon 6 was improved by adding Ethylene- n-Butyl acrylate- maleic anhydride (E-nBA-MAH) terpolymer with various concentrations from 0% (w/w) to 15% (w/w). The bare interaction energy between two polymers was investigated by using melting point depression approach utilizing both the Flory-Huggins (FH) theory and the Sanchez-Lacombe Equation of State (SL EOS). The solution of the mixture was electrospun, and the effects of process parameters on the expected radii of nanofibers were inve...
Citation Formats
G. Özden, “Synthesis and characterization of polystyrene clay nanocomposites,” M.S. - Master of Science, Middle East Technical University, 2004.