Three dimensional (3D) printing of bio-polymers from agricultural wastes

Bahçegül, Eylül Gökçe
Lignocellulosic biomass, which is a composite structure made up of cellulose, hemicellulose and lignin biopolymers, is the most abundant biopolymer resource on earth. Among the biopolymers found in lignocellulosic agricultural wastes, hemicellulose and lignin receive significantly less attention compared to cellulose for material applications despite the fact that these two biopolymers constitute almost a half of a given biomass. In this context, three novel strategies were developed that render hemicellulose and lignin 3D printable. Corn cobs (CCs) were used as the lignocellulosic resource in which hemicellulosic pastes and CC extracts in the form of thermoreversible cold-setting gels with different formulations were obtained following different extraction approaches and parameters. Water and NaOH contents as well as the extraction parameters such as KOH concentration coupled to the correct 3D printing parameters including printing temperature and speed, extrusion multiplier and layer height was the key to render the pastes and extracts 3D printable. Hemicelluloses containing lignin were rendered 3D printable for the first time without any chemical modifications and without using auxiliary polymers or additives by determining the very narrow process window that enables 3D printability. A blending strategy that relies on thermoplasticity, which involves mixing hemicellulose and lignin with polyvinyl alcohol via solvent casting, was also developed in order to obtain filaments for 3D printing, which allow for the 3D printing of more complex shapes. Thermal, mechanical, chemical, complex and apparent viscosities, morphological and printability properties of the polymers and the 3D printed materials were characterized by different methods.


3D printing of crude lignocellulosic biomass extracts containing hemicellulose and lignin
Gokce Bahcegul, E.; Bahcegul, Erinc; Özkan, Necati (2022-10-15)
© 2022 Elsevier B.V.Using lignocellulosic biomass, which is composed mainly of cellulose, hemicellulose and lignin, as a biopolymer resource in various polymeric material applications is an attractive option due to its abundance, biodegradability and renewability. Cellulose is the most popular member of the biopolymer trio for material applications, but despite constituting around half of a lignocellulosic biomass, attention hemicellulose and lignin receive is restricted in this sense, which gets even more ...
3D Printing of Hemicellulosic Biopolymers Extracted from Lignocellulosic Agricultural Wastes
Bahcegul, E. Gokce; Bahcegul, Erinc; Özkan, Necati (2020-07-01)
Despite being one of the most abundant biopolymers found in nature after cellulose, hemicellulose is still an underutilized biopolymer. Using this abundant biopolymer in 3D printing applications has a lot of potential, but so far only minor attention has been given to hemicellulose, which includes using its derivative forms together with other polymers for 3D printing. On the other hand, cellulose, in the form of cellulose derivatives or nanocelluloses such as cellulose nanofibers and nanocrystals, receives...
Tarımsal atıklardan elde edilen hemiselüloz temelli biyopolimerlerden ekstrüzyon vasıtası ile filmlerin üretilmesi
Bölükbaşı, Ufuk; Özkan, Necati; Bahçegül, Erinç; Akınalan, Büşra; Erdemir, Duygu(2014)
Majority of materials used in daily life are produced by using petroleum based polymers. However sustainability of such production processes is problematic when it is considered that petroleum is not a renewable resource in addition to the environmental pollution caused by petroleum based products. Currently, biopolymers are more frequently utilized as an alternative to petroleum based polymers. Due to their low cost because of the waste status and abundance, lignocellulosic agricultural wastes are among th...
Combined effect of point defects and layer number on the adsorption of benzene and toluene on graphene
Akay, Tugce Irfan; Toffoli, Daniele; Toffoli, Hande (Elsevier BV, 2019-06-30)
Understanding the adsorption properties of organic molecules on graphene-based substrates is important for such applications as air and water filters. Pristine graphene is often the model substrate used in the theoretical investigations of this problem. While useful, pristine single-layer graphene is however an idealized model. In this work, we assess the effect of the presence of point defects (single vacancy, divacancy, and the Stone-Wales defect) in single-layer and bilayer graphene on the energetics of ...
Hydrogen gas production by combined systems of Rhodobacter sphaeroides OU001 and Halobacterium salinarum in a photobioreactor
Zabut, Baker; EI-Kahlout, Kamal; Yucel, Meral; Gündüz, Ufuk; Turker, Lemi; Eroglu, Inci (2006-09-01)
Rhodobacter sphaeroides O.U.001 is a photosynthetic non-sulfur bacterium which produces hydrogen from organic compounds under anaerobic conditions. Halobacterium salinarum is an archaeon and lives under extremely halophilic conditions (4 M NaCl). H. salinarum contains a retinal protein bacteriorhodopsin in its purple membrane which acts as a light-driven proton pump. In this study the Rhodobacter sphaeroides O.U.001 culture was combined with different amounts of packed cells of H. salinarum S9 or isolated p...
Citation Formats
E. G. Bahçegül, “Three dimensional (3D) printing of bio-polymers from agricultural wastes,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.