title: Nanofibrillated cellulose (CNF) from eucalyptus sawdust as a dry strength agent of unrefined eucalyptus handsheets.
abstract: Nanofibrillated cellulose has been obtained from the cellulosic fraction of eucalyptus sawdust. The fractionation process involved the partial removal of hemicelluloses and lignin. CNF was obtained using TEMPO oxidation with NaOCl in basic medium followed by mechanical homogenization. The obtained CNF was subsequently used as a dry strength agent on unbleached unrefined eucalyptus pulp. The addition of 3, 6 and 9 wt.% of CNF increased lineally the tensile index of handsheets to about 55 N mg(-1) at 35°SR, compatible with papermachine runnability. The other mechanical properties also increased substantially, and porosity decreased moderately. The estimated specific surface and average diameter of these CNF were 60 m(2)g(-1), and of 41.0 nm, respectively. The addition of 9 wt.% of CNF produced an increase in mechanical strength, equivalent to that produced by PFI refining at 1600 revolutions.
authors.affiliation: Programa de Celulosa y Papel, Instituto de Materiales de Misiones, IMAM (UNaM-CONICET), Félix de Azara 1552, Posadas, Misiones, Argentina; Consejo Nacional de Investigación Científica (CONICET), Av. Rivadavia 1917, CABA, Argentina. Electronic address: mariaxvallejos@gmail.com.
authors.forename: María Evangelina
authors.initials: ME
authors.lastname: Vallejos
authors.affiliation: Programa de Celulosa y Papel, Instituto de Materiales de Misiones, IMAM (UNaM-CONICET), Félix de Azara 1552, Posadas, Misiones, Argentina.
authors.forename: Fernando Esteban
authors.initials: FE
authors.lastname: Felissia
authors.affiliation: Programa de Celulosa y Papel, Instituto de Materiales de Misiones, IMAM (UNaM-CONICET), Félix de Azara 1552, Posadas, Misiones, Argentina; Consejo Nacional de Investigación Científica (CONICET), Av. Rivadavia 1917, CABA, Argentina.
authors.forename: María Cristina
authors.initials: MC
authors.lastname: Area
authors.affiliation: Programa de Celulosa y Papel, Instituto de Materiales de Misiones, IMAM (UNaM-CONICET), Félix de Azara 1552, Posadas, Misiones, Argentina; Consejo Nacional de Investigación Científica (CONICET), Av. Rivadavia 1917, CABA, Argentina.
authors.forename: Nanci Vanesa
authors.initials: NV
authors.lastname: Ehman
authors.affiliation: Grupo de investigación LEPAMAP, Departamento de Ingeniería Química, Universitat de Girona, Campus Montilivi s/n 17071, Girona, Espagne.
authors.forename: Quim
authors.initials: Q
authors.lastname: Tarrés
authors.affiliation: Grupo de investigación LEPAMAP, Departamento de Ingeniería Química, Universitat de Girona, Campus Montilivi s/n 17071, Girona, Espagne.
authors.forename: Pere
authors.initials: P
authors.lastname: Mutjé
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry; D005052:Eucalyptus; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D013718:Tensile Strength; D014934:Wood / Q000737:chemistry
chemical_list: D003497:Cyclic N-Oxides; D002482:Cellulose; C003959:TEMPO
keywords: Biorefinery; Eucalyptus sawdust; Nanofibrillated cellulose; Papermaking; Surface addition; Wet strength additive