Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye
Tezin Onay Tarihi: 2015
Öğrenci: YURDAER BABUÇCUOĞLU
Danışman: İSMAİL TEOMAN TİNCER
Özet: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 (DGEBA) type epoxy resin (Adriapox Special) was used. Calcined Tincal, Concentrated Tincal, Ground Colemanite, Anhydrous Borax were used as filler which contain B2O3 in different percentages. The highest tensile strength (33 MPa at 2500 kGy by HDR) and the highest Young’s modulus (1095 MPa at 500 kGy by LDR) were achieved for ECOL-1 sample. The mechanical behavior of epoxy-boron samples showed a periodical line with three stages as ‘‘increment-decrement-increment’ which was related to the competition reaction between chain scission and crosslinking during irradiation by γ –rays. vi DMA results revealed that the reinforcement did not affecting the crosslinking process significantly where the increase in the Tg was consistent with the increasing in irradiation dose remarkably. TGA results showed that the weight loss of the composites was due to the degradation of the epoxy where the decomposition temperature increased about 10 °C because of the boron minerals effects. The change in the structure of the composites was affected by oxidation reaction and irradiation. The lack of adhesion between epoxy and boron minerals caused formation of weak zones to be cracked.