Fulltext

Preparation and characterization of water-redispersible nanofibrillated cellulose in powder form

Eyholzer, Ch ; Bordeanu, N. ; Lopez-Suevos, F. ; Rentsch, D. ; Zimmermann, T. ; Oksman, K.

In: Cellulose, 2010, vol. 17, no. 1, p. 19-30

Ajouter à la liste personnelle
    Titre
    • Preparation and characterization of water-redispersible nanofibrillated cellulose in powder form
    Auteur
    • Eyholzer, Ch. Swiss Federal Laboratories for Materials Testing and Research (EMPA), Dübendorf, Switzerland
    • Bordeanu, N.. Swiss Federal Laboratories for Materials Testing and Research (EMPA), Dübendorf, Switzerland
    • Lopez-Suevos, F.. Swiss Federal Laboratories for Materials Testing and Research (EMPA), Dübendorf, Switzerland
    • Rentsch, D.. Swiss Federal Laboratories for Materials Testing and Research (EMPA), Dübendorf, Switzerland
    • Zimmermann, T.. Swiss Federal Laboratories for Materials Testing and Research (EMPA), Dübendorf, Switzerland
    • Oksman, K.. Division of Manufacturing and Design of Wood and Bionanocomposites, Luleå University of Technology (LTU), Luleå, Sweden
    Type de document
    • Postprint
    Identifiant OAI-PMH
    • oai:doc.rero.ch:321971
    Summary
    Water-redispersible, nanofibrillated cellulose (NFC) in powder form was prepared from refined, bleached beech pulp (RBP) by carboxymethylation (c) and mechanical disintegration (m). Two routes were examined by altering the sequence of the chemical and mechanical treatment, leading to four different products: RBP-m and RBP-mc (route 1), and RBP-c and RBP-cm (route 2). The occurrence of the carboxymethylation reaction was confirmed by FT-IR spectrometry and 13C solid state NMR (13C CP-MAS) spectroscopy with the appearance of characteristic signals for the carboxylate group at 1,595cm−1 and 180ppm, respectively. The chemical modification reduced the crystallinity of the products, especially for those of route 2, as shown by XRD experiments. Also, TGA showed a decrease in the thermal stability of the carboxymethylated products. However, sedimentation tests revealed that carboxymethylation was critical to obtain water-redispersible powders: the products of route 2 were easier to redisperse in water and their aqueous suspensions were more stable and transparent than those from route 1. SEM images of freeze-dried suspensions from redispersed RBP powders confirmed that carboxymethylation prevented irreversible agglomeration of cellulose fibrils during drying. These results suggest that carboxymethylated and mechanically disintegrated RBP in dry form is a very attractive alternative to conventional NFC aqueous suspensions as starting material for derivatization and compounding with (bio)polymers