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: EYLÜL GÖKÇE ERGÜN
Danışman: PINAR ZEYNEP ÇULFAZ EMECEN
Özet:Renewable biopolymer resource, lignocellulosic biomass, has emerged as an alternative raw material to petroleum-based resources for the sustainable production of materials, fuels and chemicals. In this study, the main focus was to constitute a novel and eco-friendly process to fabricate films from low value lignocellulosic agricultural residues in the absence of any additional film-forming compounds. In this scope, raw lignocellulosic biomass, namely corn cobs, was turned into films using the ionic liquid 1-ethyl-3 methylimidazolium acetate ([EMIM][Ac]) as solvent. Solution preparation conditions were 140°C dissolution temperature at 1 h dissolution time. Films were also fabricated from the fractions (cellulose and hemicellulose rich portions) of corn cob. Resultant corn cob based films were evaluated and compared in terms of their morphological and physical properties. Nodular, layered and macrovoid-free structure throughout the whole cross-section of the films was observed via SEM. Films were essentially transparent, hygroscopic and absorbed significant amount of moisture, which ranged from 46% to 104% in 100% relative humidity environment. Water sensitivity of the films was reduced by heat treatment performed at 200°C. On the other hand, heat treatment was found to decrease optical transparency and increase the stiffness of the films. Among the films, the lowest water vapor permeability (WVP) value (3×10-12g.m-1.Pa-1.s-1) was measured for the corn cob film coagulated in ethanol/water mixture. The ultimate tensile strength, elastic modulus and elongation at break values of the films were in the range of 36.9-56.0 MPa, 1700-3449 MPa and 1.4-3.8%, respectively.