Hemiselüloz ekstraksiyon ve ekstrüzyon parametrelerinin farklı lignoselülozik biyokütlelerden elde edilen hemiselüloz temelli polimerik malzemelerin özelliklerine etkisi.

Abstract

There is growing interest worldwide in utilization of renewable sources for fuels, materials and chemicals due to depletion of fossil sources and the environmental damages of synthetic products. Lignocellulosic biomass is the most promising material to become a substitute for fossil sources because of its abundancy in nature, low price and utilization area which does not compete with the food. Biodegradable films can be produced from hemicellulosic part of biomass and their main use can be especially food packaging due to their low oxygen permeability. In this study, hemicellulose is extracted from corn cobs and cotton stalk by alkaline extraction and extrusion process was utilized for the production of hemicellulose based materials. Within the context of this study, alkali extraction (particle size of the corncobs, extraction time, alkaline concentration and boron compound addition) and extrusion (extrusion temperature and screw speed) parameters were investigated and compared in terms of films mechanical, thermal and morphological properties. The best conditions in the range tested, were found as 1.19 - 0.6 mm particle size corn cobs, 1 h of extraction time with 15% KOH and no boron compound addition. The tensile strength of about 80 MPa and the elongation at break of 48% were obtained for the corn cob based extruded strips. The tensile strength of about 91 MPa was obtained for the solvent casted cotton stalk films. These mechanical properties suggest that the solvent casting was a suitable method for the cotton stalk hemicellulose while the extrusion was more convenient method for the corn cob hemicellulose.M.S. - Master of Scienc