The effect of sulfate half-ester groups on cellulose nanocrystal periodate oxidation
Journal article, 2021

Periodate oxidation introduces aldehyde functionality to cellulose. The use of dialdehyde cellulose has been demonstrated for crosslinking and as a chemical intermediate towards functionalized cellulose. Commercially available cellulose nanocrystals (CNCs) typically carry a surface sulfate half-ester functionality, which results from their manufacture via sulfuric acid hydrolysis and subsequent esterification. The sulfate half-ester group is a bulky group carrying a net negative charge above pH 2 that modifies the colloidal and electro-chemical properties of the CNCs. Periodate oxidation is regioselective to the bond between carbons in positions 2 and 3 in the anhydroglucose unit while the sulfate half-ester groups are mostly considered to be located in carbon in position 6. This regioselectivity could be the reason why the role played by the sulfate half-ester group on modification by periodate oxidation has not previously been elucidated. Here, the influence of the sulfate half-ester on the oxidation of CNCs, which is shown to steer the oxidation kinetics and the properties of the resulting materials, is studied. Conventional physicochemical analysis of the oxidant consumption is accompanied by elemental analysis, Fourier-transform infrared, X-ray photoelectron and solid-state nuclear magnetic resonance spectroscopy, and wide-angle x-ray scattering analyses; the zeta potential is used to characterize the colloidal properties of the suspensions and atomic force microscopy for determining particle dimensions. The presence of the sulfate half-ester group decreases the rate of oxidation. However, the content of the sulfate half-ester groups decreases when degree of oxidation reaches approx. 50%. We demonstrate that the CNC surfaces are affected by the oxidation beyond the C2–C3 bond cleavage: insight into the kinetics of the oxidation process is a prerequisite for optimizing CNC oxidation.

Sulfate half-esters

Cellulose nanocrystals

Periodate oxidation

Author

Saül Llacer Navarro

Chalmers, Electrical Engineering

Wallenberg Wood Science Center (WWSC)

Koyuru Nakayama

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Lars Evenäs Group

Wallenberg Wood Science Center (WWSC)

Alexander Idström

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Lars Evenäs Group

Lars Evenäs

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Lars Evenäs Group

Wallenberg Wood Science Center (WWSC)

Anna Ström

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Anna Ström Group

Tiina Nypelö

Wallenberg Wood Science Center (WWSC)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Cellulose

0969-0239 (ISSN)

Vol. In Press

Subject Categories

Inorganic Chemistry

Polymer Technologies

Other Chemistry Topics

DOI

10.1007/s10570-021-04115-y

More information

Latest update

8/25/2021