The effect of inorganic composites on the thermal degradation of Poly(methylmetacrylate) (PMMA)

Download

index.pdf

Date

2011

Author

Karabulut, Meryem

Metadata

Show full item record

Item Usage Stats

272
views

174
downloads

Metal coordinated polymer nanocomposites have gained great attention due to their superior characteristics. Polymethylmethacyrlate (PMMA) is the most commonly used polymer since it is easily processed. In this study, modified TiO2 nanoparticles prepared by insitu and exsitu methods were embedded into PMMA in order to improve its thermal stability and the effects of TiO2 nanoparticles on thermal characteristics of PMMA were investigated by direct pyrolysis mass spectrometry. The insitu method which is a sol gel method, TiO2/SiO2 nanoparticles were synthesized by mixing titanium(IV) tetraisopropoxide, TTIP, with silane coupling agent, 3-(3-methoxysilyl)methylmetacrylate, MSMA in absolute ethanol. In exsitu method, TiO2 powder was directly mixed with silane coupling reagent. TiO2/SiO2 nanoparticles were embedded into the PMMA by direct mixing resulting in exsitu and insitu TiO2/SiO2/PMMA nanocomposites. The synthesized TiO2/SiO2/PMMA nanocomposites were characterized by TEM, ATR-FT-IR and analyzed for the investigation of their reaction mechanism and thermal characteristics by pyrolysis mass spectroscopy. iv TEM images confirmed the formation of TiO2/SiO2 nanoparticles and TiO2/SiO2/PMMA nanocomposites and indicated that the average particle size of TiO2/SiO2 nanoparticles was around 6 nm whereas average particle size of SiO2/TiO2/PMMA nanocomposites were around 25 nm. The increase in the size of nanoparticles is associated with incorporation of TiO2/SiO2 nanoparticles into PMMA matrix. ATR-FTIR spectrum of 5% TiO2/SiO2/PMMA nanocomposites showed the formation of TiO2/SiO2 nanopartciles clearly. Pyrolysis mass spectrometry analysis revealed that incorporation of TiO2/SiO2 nano- particles into PMMA resulted in higher thermal stability only for low weight percentage insitu TiO2/SiO2/PMMA. At high weight percentages a decrease in thermal stability was detected. On the other hand, in case of exsitu TiO2/SiO2/PMMA, contrary to our expectations a decrease in thermal stability was detected. The decrease in thermal stability was attributed to evolution of methacrylic acid during thermal degradation of silane groups.

Subject Keywords

Chemistry, Inorganic., Polymers

URI

http://etd.lib.metu.edu.tr/upload/12613752/index.pdf
https://hdl.handle.net/11511/21004

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Synthesis and characterization of osmium(0) nanoclusters and their catalytic use in aerobic alcohol oxidation Akbayrak, Serdar; Özkar, Saim; Department of Chemistry (2011) Transition metal nanoclusters are more active and selective catalysts than their bulk counterparts as the fraction of surface atoms increases with the decreasing particle size. When stabilized in organic or aqueous solutions, they can catalyze many reactions. The catalytic activity of metal nanoclusters depends on the particle size and size distribution. Particle size can be controlled by encapsulating the nanoclusters in the cavities of highly ordered porous materials such as zeolites. In this project, osm...
Effect of surface treatment on electrical conductivity of carbon black filled conductive polymer composites Koysuren, Ozcan; Yesil, Sertan; Bayram, Göknur (Wiley, 2007-06-05) Two different types of surface modifiers, 3-aminopropyltriethoxysilane and formamide, were applied to carbon black (CB) particles to lower electrical resistivity of polymer composites prepared by treated CB. Two different matrices, low-density polyethylene and nylon 6, were chosen to compound with surface modified CB. Surface energy of CB was increased by adding amine or amide functional groups during surface treatment of CB. According to electron spectroscopy for chemical analysis (ESCA), chemical modifica...
Large strain and small-scale biaxial testing of sheet metals Seymen, Yadigar; Efe, Mert; Department of Metallurgical and Materials Engineering (2016) Small-scale and multi-axial testing of sheet metals, particularly of lightweight alloys and advanced high strength steels (AHSS) are becoming important as these materials exhibit forming behavior sensitive to their unique microstructural features and strain paths. As an alternative to large-scale standard tests, in this study, a novel biaxial tensile test apparatus for miniature cruciform samples is introduced. The compact and portable apparatus includes a custom-built optical microscope and high-resolution...
Modeling of spherulite microstructures in semicrystalline polymers Oktay, H. Emre; Gürses, Ercan (2015-11-01) Semicrystalline polymers are composed of crystalline structures together with amorphous polymer chain networks and therefore they exhibit deformation mechanisms of both crystalline materials and amorphous polymers. One of the most common microstructures observed in semicrystalline polymers is the spherulite microstructure in which crystalline lamellae are embedded in a matrix of amorphous material and grow out from a common central nucleus in radial directions. The mechanical behavior of semicrystalline pol...
Preparation and characterization of magnetic nanoparticles Küçük, Burcu; Volkan, Mürvet; Department of Chemistry (2009) Magnetite (Fe3O4) and Maghemite (γ-Fe2O3) are well-known iron oxide phases among magnetic nanoparticles due to their magnetic properties, chemical stability, and nontoxicity. They have gained acceptance in several fields of application of nanomaterials such as magnetic recording systems, magnetic refrigeration, magneto-optical devices, magnetic resonance imaging, magnetic separation techniques and separation and purification of biological molecules. Recently, there is a growing interest in the synthesis of ...

Citation Formats

M. Karabulut, “The effect of inorganic composites on the thermal degradation of Poly(methylmetacrylate) (PMMA),” M.S. - Master of Science, Middle East Technical University, 2011.