Industrial Crops and Products 76 (2015) 166–173 Contents lists available at ScienceDirect Industrial Crops and Products jo u r n al homep age: www.elsevier.com/locate/indcrop All-lignocellulosic fiberboard from corn biomass and cellulose nanofibers Dyna Theng a,c , Gerard Arbat b,∗ , Marc Delgado-Aguilar a , Fabiola Vilaseca a , Bunthan Ngo c , Pere Mutjé a a Grupo LEPAMAP, Departamento de Ingeniería Química, Universitat de Girona, Spain b Departamento de Ingeniería Agraria y Tecnología Agroalimentaria, Universitat de Girona, Spain c Royal University of Agriculture, Cambodia a r t i c l e i n f o Article history: Received 6 February 2015 Received in revised form 18 June 2015 Accepted 20 June 2015 Keywords: Corn biomass Binderless fiberboard HDF Cellulose nanofibers a b s t r a c t In general, fiberboards are made of lignocellulosic fibers with synthetic adhesive to connect between fibers. Synthetic adhesives are usually non-biodegradable constituents and they cause health and envi- ronmental troubles. The present study aims to develop fiberboards from corn thermomechanical fibers reinforced with cellulose nanofibers. In this work, corn stalk biomass was used to produce high yield thermomechanical pulp (TMP) that was converted into binderless fiberboards. Cellulose nanofibers (CNF) were also added as reinforcing agent. The mechanical and physical properties of the resulting fiberboards were characterized and compared with commercial high density fiberboard (HDF) containing synthetic adhesives. Fiberboards with 0.5 wt% CNF showed modulus of rupture of 43 MPa, similar to that of com- mercial HDF. The highest mechanical performance was reached for fiberboards at 2 wt% of CNF, with modulus of rupture of 52 MPa. CNF was found to increase the resistance of the new all-lignocellulosic fiberboards when compared to the products made only with corn stalk fiber, and also when compared with commercial HDF. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Fiberboards are fibrous panels made up of lignocellulosic mate- rials joined together with a synthetic binder (American National Standard, 2002). Urea-formaldehyde or phenol-formaldehyde are common resins used in fiberboard manufacturing because they are less expensive compared with other adhesives. However, the formaldehyde emission is one of the most important disadvantages of these resins, since it can potentially cause health and pollution problems. Instead, binderless boards are wood-based composites consisting of particles of lignocellulosic material bonded together without any added resin. Recently, there is a growing request for binderless boards (El-Kassas and Mourad, 2013; Rokiah et al., 2009). In order to meet the market demand and environmental care, sev- eral studies have been done to convert fiberboards into binder-free fiberboards by using different methods such as thermotreatments (Anglès et al., 2001; Baskaran et al., 2012; Halvarsson et al., 2009; Huang et al., 2015; Mejía et al., 2014; Pan et al., 2010; Quintana et al., 2009; Rokiah et al., 2009; Saari et al., 2014 Wuzella et al., 2011); the ∗ Corresponding author. E-mail address: gerard.arbat@udg.edu (G. Arbat). replacement of urea formaldehyde by starch (Abbott et al., 2012); the addition of soybean protein (Ciannamea et al., 2010; Li et al., 2009); pretreating fibers with white-rot fungus (Wuzella et al., 2011); the addition of lignin (Anglès et al., 2001; Mancera et al., 2012; Mejía et al., 2014; Sun et al., 2014; Velásquez et al., 2003); and more lately, by adding of cellulose nanofibers (Cui et al., 2014). The present study aims to develop fiberboards from thermome- chanical fibers produced from corn biomass. Additionally, cellulose nanofibers will be incorporated to improve the mechanical effi- ciency of the corn fiberboards. Corn biomass will be treated by steaming in a rotary digester, and later mixed with eucalyptus cel- lulose nanofibers. The final purpose is to produce corn binder-free fiberboards with enhanced properties with respect to commercial fiberboard containing synthetic adhesives. 2. Materials and methods 2.1. Materials The basic materials used in the research were corn biomass and bleached Kraft Eucalyptus pulp. Corn residues were col- lected from field at La Tallada d’Empordà, Spain, composed of about 12% humidity, kept at room temperature and used for the http://dx.doi.org/10.1016/j.indcrop.2015.06.046 0926-6690/© 2015 Elsevier B.V. All rights reserved.