Date

2014

Author

Yürekli, Elif

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Epoxy resin is one of the most important thermosetting polymers, widely used in various fields of industry. However, like most of the polymeric materials, epoxy resins are flammable and this restricts their application areas. The purpose of this thesis is to increase flame retardant property of epoxy-based composites using various flame retardant additives mainly including barium metaborate. This thesis consists of three main parts. In the first part, preliminary composites, which containing barium metaborate (BaM), zinc borate (ZnB), melamine phosphate (MP), melamine polyphosphate (MPP), red phosphorus (RP), pentaerythritol (PER) and dipentaerythritol (DPER), were given. In accordance with the results of preliminary experiments, the information about the flame retardant types and amounts was obtained to create formulations of final composites. In the second part of the thesis, the final composites were prepared using MP, DPER, ZnB, and calcium borate (CaB) in addition to BaM and methacrylate epoxy cyclosiloxane (MEC). The produced composites were characterized by scanning electron microscopy (SEM), limiting oxygen test (LOI) test, the vertical burning test (UL-94), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), tensile and impact tests. The LOI value of neat epoxy was measured as 19%. 10% MP and 1% BaM containing epoxy-based composite was 27% in LOI value and UL-94 test result was determined as V-0. Also, when concentration of the additives increased in the epoxy matrix, it was seen that tensile strength and elongation at break value of the composites decreased; however tensile moduli of the composites increased in general. In the last part of the thesis, pure epoxy and epoxy-based composites were subjected to accelerated weathering test. They were exposed to UV radiation and moisture for 300 hours. Exposed samples were characterized by SEM and impact test. Furthermore, samples were photographed before and after the accelerated weathering test in order to show physical change that occurred in the samples. According to the impact test results, the impact strength of all the weathered composites decreased when compared to unweathered composites.

Subject Keywords

Barium., Borates., Epoxy resins., Fire resistant polymers.

URI

http://etd.lib.metu.edu.tr/upload/12617841/index.pdf
https://hdl.handle.net/11511/23840

Collections

Graduate School of Natural and Applied Sciences, Thesis