András Bartos, Juliana Anggono, Ágnes Elvira Farkas, Dávid Kun, Felycia Edi Soetaredjo, János Móczó, Antoni, Hariyati Purwaningsih, Béla Pukánszky
Lignocellulosic fibers extracted from sugarcane bagasse were treated with NaOH solutions of different concentration (0-40 wt%) to study the effect of alkali treatment on the composition, structure and properties of the fibers. Composition was determined by the van Soest method, structure was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), while mechanical properties by tensile testing. Hemicellulose and lignin content decrease, while cellulose content goes through a maximum as a function of alkali concentration. Crystallinity changes only slightly and microfibril angle (MFA) remains constant thus structural effects and especially MFA are not the primary reasons for changing properties. The Young's modulus of the fibers shows a slight maximum at around 2-4 wt% NaOH content, while tensile strength goes through a much more pronounced one at around 5-8 wt%. Direct correlation between structure and mechanical properties was not found indicating that composition is more important in the determination of properties than structure. Regression analysis proved that the combination of several compositional variables determines mechanical properties in a non-linear manner. The improvement in fiber properties was explained with the dissolution of weak amorphous fractions and the relative increase of cellulose content. © 2020 The Authors
Laboratory of Plastics and Rubber Technology, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, P.O. Box 91, Budapest, H-1521, Hungary; Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, P.O. Box 286, Budapest, H-1519, Hungary; Department of Mechanical Engineering, Petra Christian University, Jalan Siwalankerto 121-131, Surabaya, 60236, Indonesia; Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Jalan Kalijudan 37, Surabaya, 60114, Indonesia; Department of Civil Engineering, Petra Christian University, Jalan Siwalankerto 121-131, Surabaya, 60236, Indonesia; Department of Materials and Metallurgical Engineering, Sepuluh Nopember Institute of Technology, Surabaya, 60111, Indonesia