Reinforcement of polyesters by boron minerals

Download

index.pdf

Date

2015

Author

Akgün, Aydın Mert

Metadata

Show full item record

Item Usage Stats

187
views

78
downloads

Polymers are used in areas where exposure to high-energy radiation might occur. Main effects of irradiation on polymers are crosslinking, chain scission and oxidation. Radiation resistance of polymers depends on structure, additives, or irradiation conditions. Since boron is highly effective material against radiation, especially against neutron radiation, with its high absorption cross section, boron products is used for radiation applications. The aim of this study is to investigate the effects of different types of boron minerals used as reinforcing fillers on mechanical properties, thermal properties and on radiation stability of unsaturated polyester resin. Four different boron minerals (anhydrous borax, calcined tincal, concentrated tincal and ground colemanite) with various B2O3 content were used in this study. Unsaturated polyester composites were prepared with 2%, 5% and 10% of boron mineral by weight. They were exposed to gamma radiation with irradiation dose rates of 30 Gy/h and 2500 Gy/h. Samples were characterized by ATR-FTIR, TGA, DMA and SEM techniques as well as their mechanical properties. Most satisfying mechanical test results were obtained for anhydrous borax which contains 68% of B2O3. Polystyrene formation and oxidizing reactions especially at high doses were observed from ATR-FTIR spectra. Tg of neat polyester resin was shifted from 66.3 to 74.3 °C for high doses. Neat polyester resin was thermally degraded around 410 °C and thermal stability of composites was not significantly affected by irradiation or reinforcement as seen from TGA thermograms. Agglomeration derived from higher reinforcing filler ratio was seen from SEM micrographs.

Subject Keywords

Boron., Polyesters., Scission (Chemistry)., Crosslinking (Polymerization).

URI

http://etd.lib.metu.edu.tr/upload/12619368/index.pdf
https://hdl.handle.net/11511/25190

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Reinforcement of epoxies by boron minerals Babuçcuoğlu, Yurdaer; Tinçer, Teoman; Özdemir, Tonguç; Department of Polymer Science and Technology (2015) As polymers/fillers have shown much improved mechanical and thermal properties, the subject of epoxy resin reinforcement using boron minerals fillers has become valuable subject to study. The aim of this study is how boron minerals influence epoxy resins’ mechanical and thermal properties under gamma irradiation. The effects of boron on the mechanical and thermal properties of epoxy were studied in terms of mineral type, mineral loading concentration and irradiation dose in air and under vacuum. Bisphenol-A...
Investigating Glow Discharge Detectors as a Millimeter-Wave/Terahertz Radiation Detection Tool Alasgarzade, N.; Nebioglu, M. A.; Takan, T.; Uzun Kaymak, İlker Ümit; Şahin, Asaf Behzat ; Altan, Hakan (2015-11-05) Compared to other forms of electromagnetic radiation, Terahertz (THz) radiation is considered safe for imaging and detection purposes due to their non-invasive and non-destructive nature. Novel techniques and methods are constantly being evaluated for efficient detection and measurements of THz waves, yet their commercial success is limited due to cost and overall complexity of these systems. Commercially available Glow Discharge Detectors (GDDs) are proven to detect microwave and higher frequency radiation...
Investigating Glow Discharge Detectors as a Millimeter-Wave/Terahertz Radiation Detection Tool Uzun Kaymak, İlker Ümit; Takan, Taylan; Alasgarzade, Namıg; Şahin, Asaf Behzat; Altan, Hakan (2015-11-06) Compared to other forms of electromagnetic radiation, Terahertz (THz) radiation is considered safe for imaging and detection purposes due to their non-invasive and non-destructive nature. Novel techniques and methods are constantly being evaluated for efficient detection and measurements of THz waves, yet their commercial success is limited due to cost and overall complexity of these systems. Commercially available Glow Discharge Detectors (GDDs) are proven to detect microwave and higher frequency radiation...
Synthesis of New Flexible Coumarin Dimers for Sodium and Potassium Differentiation TAN, DUYGU; Akdağ, Akın (Springer Science and Business Media LLC, 2020-01-01) Using fluorescence to detect biologically relevant metals has been studied extensively due to its rapid and low detection limit ability. Sodium and potassium differentiation is significant in diagnosis of many medical conditions. For this, we designed coumarin dimers as flexible fluorescent probes using ethylene glycol units for differentiation of sodium and potassium. To our best knowledge, use of these easy-to-synthesize coumarin dimers linked through ethylene glycol units are first in the literature. In ...
Use of Al(2)O(3) layer as a dielectric in MOS based radiation sensors fabricated on a Si substrate YILMAZ, ERCAN; Dogan, Ilker; Turan, Raşit (Elsevier BV, 2008-11-01) The use of Al(2)O(3) dielectric in MOS based radiation sensors has been investigated. Their response has been compared with conventional MOS capacitors with a SiO(2) dielectric. The study includes gamma radiation effects with dose up to 4 Gy. The effect of radiation has been determined from the valance band shift in CV curves. The amount of charge induced by the radiation has been calculated and compared with the response of MOS capacitors with SiO(2) with the same and different thicknesses. Fading properti...

Citation Formats

A. M. Akgün, “Reinforcement of polyesters by boron minerals,” Ph.D. - Doctoral Program, Middle East Technical University, 2015.