Increased thermal stability of nanocellulose composites by functionalization of the sulfate groups on cellulose nanocrystals with azetidinium ions
Journal article, 2018

Cellulose nanocrystals (CNCs) prepared via sulfuric acid hydrolysis are decorated with sulfate groups that yield a stable water suspension. To make the CNCs adaptable for use in composites, the hydroxyl groups on the surface are usually hydrophobized. In this article, an alternative hydrophobization method is described in which the sulfate groups are conjugated with azetidinium salts. The results of this study show that the sulfate groups can be functionalized with azetidinium salts and from thermal studies, it was discovered that the functionalization led to a 100 degrees C increase in thermal stability, compared with unmodified CNCs. The nanocomposites prepared by extrusion of CNC-coated low-density polyethylene powder displayed similar mechanical properties as the CNC-reference sample, but without the discoloration, due to the increased thermal stability. In conclusion, the azetidinium reagent reacts preferentially with sulfate groups, and this new type of chemical conversion of sulfate groups on polysaccharides will be beneficial in nanocomposite manufacturing.

nanowires and nanocrystals

cellulose and other wood products

nanoparticles

biopolymers and renewable polymers

functionalization of polymers

Author

Mikaela Börjesson

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Organic Chemistry

Karin Sahlin

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Organic Chemistry

Gunnar Westman

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Organic Chemistry

Journal of Applied Polymer Science

0021-8995 (ISSN) 1097-4628 (eISSN)

Vol. 135 10 Art no: 45963-

Subject Categories

Polymer Chemistry

DOI

10.1002/app.45963

More information

Created

1/10/2018