Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2014
Öğrenci: MİRAY YAŞAR
Danışman: GÖKNUR BAYRAM
Özet:Thermoplastic elastomers (TPEs) have extensive use of areas because of their unique structure due to having both hard and soft segments together in their structure. However, their disadvantages such as high cost of raw materials, low thermal stability and difficult processing in extrusion because of having low melting viscosity restrict their use in industrial applications. The main objective of this study is to modify multifunctional properties of one class of TPE, thermoplastic poly(ether)ester elastomer (TPEE), and to obtain thermally and electrically stimulated shape memory properties while overcoming the disadvantages and the loss of mechanical properties. For this purpose, TPEE-based binary, ternary and quaternary composites were prepared from unmodified carbon black (UMCB), modified carbon black (mCB), Ethylene Glycidyl Methacrylate (E-GMA) elastomer and/or paraffinic oil. The second objective of the study is to prepare carbon fabric reinforced multilayer composites (CFRC) using TPEE with improved properties. It is also aimed to characterize binary, ternary and quaternary composites/blends & multilayer composites in terms of their mechanical, electrical, shape memory, thermal properties and morphologies. According to the results of binary composites, tensile and impact properties decreased with increasing UMCB contents because of agglomerations. The composite with 3wt% UMCB was a semi-conductor (6x103 ohm.cm). This amount was selected as optimum UMCB content to sustain mechanical properties. Among oil containing binary blends, 1wt% oil had the highest elongation at break (255.6%), highest impact strength (22.3kJ/m2) and best shape recovery ratio (99.9%). Over 10wt% E-GMA content, elongation at break significantly decreased to 206.7%. As a result, 3wt% mCB or UMCB, 1wt% oil and/or 10wt% E-GMA were incorporated into the TPEE matrix to prepare ternary and quaternary composites. Ternary blends with oil and E-GMA had higher tensile, impact and shape memory properties than their binary blends. E-GMA lost all of its effects when incorporated into TPEE with UMCB/mCB. Carbon fabric reinforced multilayer composites were prepared with five different selected composites and neat TPEE. Highest impact strength as 112.2kJ/m2 was obtained from mCB containing quaternary multilayer composites. Tensile modulus of neat TPEE was significantly improved with 3wt% mCB and 1wt% oil containing ternary multilayer composites to 9340.7 MPa. More conductive composites were obtained with the preparation of multilayer composites. Among studied CFRC, TPEE/3wt%mCB containing multilayer composite showed highest shape recovery ratio of 84.1%.