RT Journal Article
T1 The relevance of the pretreatment on the chemical modification of cellulosic fibers
A1 Aguado, Roberto J.
A1 Lourenço, Ana F.
A1 Ferreira, Paulo J.T.
A1 Moral, Ana
A1 Tijero, Antonio
K1 Activation
K1 Cationization of cellulose
K1 Degree of crystallinity
K1 Pretreatment
K1 Swelling
K1 X-ray diffraction
AB Cationized fibers and other kinds of chemically modified fibers impart many advantages in papermaking, but unfeasibly long reaction times are necessary to attain acceptable degrees of substitution, due to the low reactivity of bleached kraft pulps. In this work, different aqueous pretreatments were tested in order to activate cellulose towards a 60 min-long etherification with a quaternary ammonium reagent. Severe decrystallization treatments, namely alkalization with NaOH 20%, NaOH/urea or FeTNa, conducted to the best reactivity results (substitution from 2 to 10%), but the fiber properties were harshly affected. Pretreatments involving H3PO4 at different concentrations were also performed, with distinct results, from unnoticeable effects at 20% to amorphization and excessive depolymerization at 80%. Finally, aqueous ammonium thiocyanate was tested as activator and had little effect on fibers, although the addition of ammonia resulted in high degrees of substitution, while maintaining the pulps’ capability to retain inter-fiber water and cellulose I as the prevalent allomorph.
PB SPRINGER LINK
YR 2019
FD 2019-05-20
LK https://hdl.handle.net/10433/19574
UL https://hdl.handle.net/10433/19574
LA en
NO The relevance of the pretreatment on the chemical modification of cellulosic fibers. Cellulose, vol 26, p. 5925–5936
NO ECOWAL Group, Molecular Biology and Biochemical Engineering Department, Universidad Pablo de Olavide, ES-41013 Seville, Spain
NO Chemical Engineering Department, CIEPQPF, University of Coimbra, 3030-790, Coimbra, Portugal
NO Grupo de Celulosa y Papel, Chemical Engineering Department, Complutense University of Madrid, 28040, Madrid, Spain
DS RIO
RD May 22, 2026