“Dialdehyde Cellulose” Nanofibers by Electrospinning as Polyvinyl Alcohol Blends: Manufacture and Product Characterization

Abstract

A nanofiber was obtained by electrospinning of “dialdehyde cellulose” (periodate-oxidized cellulose, DAC) and polyvinyl alcohol (PVA), using only water as the solvent. Celluloses of four different origins were fully oxidized with sodium periodate to water-soluble DAC. Aqueous solution of DAC showed inadequate spinnability regardless of the polymer concentration and the electrospinning conditions used. Addition of PVA improved the solution's viscoelasticity and, consequently, the solution's spinnability. We examined the effects of DAC/PVA composition and electrospinning parameters on fiber morphology. Highly homogeneous nanofibers were prepared from 1:1 up to 2:1 (weight) DAC/PVA blends while samples of lower viscosity or higher relative DAC contents resulted in continuous, beaded fiber networks. Characterization of the electrospun fabrics revealed a highly crosslinked DAC structure reinforced with PVA, strongly interacting through hemiacetal bonds and hydrogen bonding. Fluorescence labeling confirmed the presence of reactive aldehyde functionalities in the electrospun web. The versatile properties of DAC as reactive material can now be imparted on electrospun fiber and nanofiber material – which was not possible so far –further widening the application scope of this interesting cellulose derivative.

KEYWORDS:

• Cellulose
• dialdehyde cellulose
• electrospinning
• composite nanofiber
• periodate oxidation
• viscose

ACKNOWLEDGMENTS

We thank M. Bacher and I. Sulaeva, BOKU University, for NMR and SEC measurements, respectively. The Institute of Wood Technology and Renewable Materials at BOKU is acknowledged for access to rheological and thermal analysis equipment.

SUPPLEMENTARY DATA

Supplementary data for this article can be accessed on the publisher's website at https://doi.org/10.1080/02773813.2017.1381743

ABBREVIATIONS

DAC	=	dialdehyde cellulose
DACv	=	viscose fibers DAC
DACb	=	beech kraft pulp DAC
DACe	=	eucalyptus sulfite pulp DAC
DACc	=	cotton linters DAC
DO	=	degree of oxidation
TGA	=	thermogravimetric analysis
FTIR	=	fourier transform infrared
MWD	=	molecular weight distribution
Mw	=	weight average molar mass
NMR	=	nuclear magnetic resonance
PVA	=	poly(vinyl alcohol)
SEC	=	size exclusion chromatography
SEM	=	scanning electron microscopy

Additional information

Funding

This work was funded by the Austrian Research Promotion Agency (FFG.) under the scope of the FLIPPR (Future Lignin and Pulp Processing Research) project. Shinshu University is gratefully acknowledged for providing financial support to S. H. during her international exchange.