Silicon-based preceramic polymers and their uses in polymer composites: synthesis, characterization and processing

Download

index.pdf

Date

2011

Author

Dönmez Karadal, Sibel

Metadata

Show full item record

Item Usage Stats

275
views

64
downloads

The objectives of this study are to synthesize poly(dimethylsilane) (PDMS) preceramic polymer and to investigate its effect on morphology, flame retardant and mechanical properties of polypropylene (PP) based composites. There are mainly two parts in this thesis. In the first part, PDMS was synthesized by electrochemical polymerization of dichlorodimethylsilane, which was dissolved in 1,2 dimethoxyethane (DME) solvent consisting of tetrabutyl ammonium perchlorate (TBAP), as supporting electrolyte. PDMS was obtained in powder form and characterized with Fourier transform infrared, ultraviolet-visible and proton nuclear magnetic resonance spectroscopic analyses, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Since PDMS has some impurities coming from TBAP and DME, alternatively, the PDMS synthesis was done by electrochemical reduction of dichlorodimethylsilane without using solvent and/or supporting electrolyte for seven days. PDMS was produced as pure and characterized with the same methods used for previous synthesis. In the second part of this thesis, PP based composites with additives were prepared by using a twin-screw extruder and injection molding machine and were characterized with limiting oxygen index (LOI), horizontal burning, TGA, differential scanning calorimetry (DSC), tensile and impact tests and SEM analysis. Triphenyl phosphate, boron phosphate, magnesium hydroxide, intumescent flame retardants (IFR) (melamine phosphate (MP) and pentaerythritol (PER)), antimony trioxide and poly(methylsilsesquioxane) were additives used in this study other than PDMS. According to LOI test results, the highest LOI value among the PDMS composites was obtained in 1% PDMS, 14.25% MP and 4.75% PER (w/w) containing composite as 24%, whereas the LOI value of neat PP was measured as 17.5%. It was determined that elastic moduli of all the composites studied were higher than neat PP.

Subject Keywords

Chemical engineering., Polymers.

URI

http://etd.lib.metu.edu.tr/upload/12613955/index.pdf
https://hdl.handle.net/11511/20838

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Microwave initiated polymerization of trihalophenyleneoxide and aniline Levent, Fulya; Kısakürek, Duygu; Toppare, Levent Kamil; Department of Polymer Science and Technology (2011) The aim of the study is to synthesize poly(dibromophenyleneoxide) and polyaniline separately applying different microwave energies (90-900 watt), water amounts (1-5 ml) and time intervals (2-10 min) and investigate the effects of these parameters on the percent conversion of the polymers. The synthesis of poly(dibromophenyleneoxide) (P), radical ion polymer (RIP) and crosslinked polymer (CLP) were achieved by using tribromophenol (TBP) and Ca(OH)2 via microwave energy in a very short time interval. P and RI...
Chiral seperations by enzyme enhanced ultrafiltration : fractionation ofracemic benzoin Ölçeroğlu, Ayşe Hande; Yılmaz, Levent; Department of Chemical Engineering (2006) In this study, a methodology for separation of chiral molecules, by using enhanced ultrafiltration system was developed. Benzoin was the model chiral molecule studied. In the scope of developing this methodology, some parameters were investigated in the preliminary ultrafiltration experiments in order to set the operation conditions for enhanced ultrafiltration experiments. Due to the slight solubility of benzoin in pure water, 15% (v/v) Polyethylene glycol (PEG 400) and 30 % (v/v) Dimethyl sulfoxide (DMSO)...
Kinetic studies for the production of tertiary ethers used as gasoline additives Boz, Nezahat; Doğu, Timur; Department of Chemical Engineering (2004) In the present study, the kinetics studies for etherification reactions were investigated in detail. In the first phase of present study, different acidic resin catalysts were prepared by the heat treatment of Amberlyst-15 catalysts at 220°C at different durations of time and also by the synthesis of sulfonated styrene divinylbenzene cross-linked resins at different conditions. A linear dependence of reaction rate on hydrogen ion-exchange capacity was in 2M2B+ethanol reaction. However, in the case of 2M1B+e...
Electrochemical synthesis of poly(methylsilyne), and the effect of silicon-based preceramic polymers on the properties of polypropylene based composites Eroğlu, Damla; Bayram, Göknur; Department of Chemical Engineering (2008) In the first part of this dissertation, poly(methylsilyne) was produced both in small and large-scales. In the small-scale, the aim was to synthesize the polymer by electrochemical polymerization of methyltrichlorosilane at a constant potential of -6 V supplied by batteries, using sodium dodecyl sulfate (SDS) as the supporting electrolyte. The polymer was characterized by 1H-NMR, FTIR, UV-Visible Spectroscopy and GPC in addition to its distinctive yellow color. The yellow color and the 1H-NMR, FTIR, UV-Visi...
Metal polymer composite nanofiber production by electrospinning Karakoç, Nihan; Gündüz, Güngör; Department of Chemical Engineering (2009) This study aims synthesis of metal/polymer one dimensional nanostructures by micelle formation, reduction, and electrospinning route, and to analyze the morphological characteristics of composite nanofibers. The study was carried out in three main steps. First, the reverse micelle structures were established between the anionic surfactant and the metal ion. The surfactant acts as an agent to bind metal ions together so that the arrangements of metal ions can be controlled in the solution. As the surfactant ...

Citation Formats

S. Dönmez Karadal, “Silicon-based preceramic polymers and their uses in polymer composites: synthesis, characterization and processing,” M.S. - Master of Science, Middle East Technical University, 2011.