Preparation of cellulose nanomaterials via cellulose oxalates

Jonatan Henschen; Dongfang Li; Monica Ek

doi:10.1016/j.carbpol.2019.02.056

Preparation of cellulose nanomaterials via cellulose oxalates

Carbohydr Polym. 2019 Jun 1:213:208-216. doi: 10.1016/j.carbpol.2019.02.056. Epub 2019 Feb 18.

Authors

Jonatan Henschen¹, Dongfang Li², Monica Ek³

Affiliations

¹ Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden. Electronic address: hens@kth.se.
² Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden. Electronic address: dongfan@kth.se.
³ Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden. Electronic address: monicaek@kth.se.

PMID: 30879662
DOI: 10.1016/j.carbpol.2019.02.056

Abstract

Nanocellulose prepared from cellulose oxalate has been discussed as an alternative to other methods to prepare cellulose nanofibrils or crystals. The current work describes the use of a bulk reaction between pulp and oxalic acid dihydrate to prepare cellulose oxalate followed by homogenization to produce nanocellulose. The prepared nanocellulose is on average 350 nm long and 3-4 nm wide, with particles of size and shape similar to both cellulose nanofibrils and cellulose nanocrystals. Films prepared from this nanocellulose have a maximum tensile stress of 140-200 MPa, strain at break between 3% and 5%, and oxygen permeability in the range of 0.3-0.5 cm³ μm m^-2 day^-1 kPa^-1 at 50% relative humidity. The presented results illustrate that cellulose oxalates may be a low-cost method to prepare nanocellulose with properties reminiscent of those of both cellulose nanofibrils and cellulose nanocrystals, which may open up new application areas for cellulose nanomaterials.

Keywords: Cellulose; Cellulose nanocrystals; Cellulose nanofibrils; Cellulose oxalate; Nanocellulose; Oxalic acid dihydrate.