Title: Influence of drying restraint on physical and mechanical properties of nanofibrillated cellulose films
Author: Baez, Carlos; Considine, John; Rowlands, Robert;
Source: Cellulose Volume 21, 2014; pp. 347-356.
Publication Series: Scientific Journal (JRNL)
Description: Nanofibrillated cellulose (NFC) is a renewable and biodegradable fibril that possesses high strength and stiffness resulting from high level hydrogen bonding. Films made from NFC shrink and distort as they transition from a wet state (20 wt% solids) to a state of moisture equilibrium (90 wt% solids at 50 % RH, 23 °C). Material distortions are driven by development of moisture gradients within the fibril network and effectively reduce mechanical performance. For this study, NFC was extracted from softwood holocellulose by first employing a chemical pretreatment [(2,2,6,6tetramethylpiperidin-1-yl)oxyl catalyzed oxidation] followed by mechanical fibrillation using ultrasound energy. To assess the problem of film distortion, neat NFC films were dried at 50 % RH, 23 °C under one of the following three restraint conditions: fully restrained, partially restrained, and uniaxially drawn. The influence of restraint condition on the resulting physical and mechanical properties was evaluated. Raman and X-ray results showed that fibrils in the uniaxially drawn specimens tended to align with the drawing axis, whereas no in-plane orientation effects were observed for the fully or partially restrained specimens. Fully restrained specimens had a respective strength and stiffness of 222 MPa and 14 GPa in every (in-plane) direction. However, samples that were wet-drawn to a 30 % strain level had a respective strength and stiffness of 474 MPa and 46 GPa in the direction of draw. Mechanical properties for axially drawn specimens had both fibril alignment and fibril straightening contributions.
Keywords: nanofibrillated cellulose, mocrofibrillated cellulose, nanocellulose restraint drying, fiber orientation, cellulose nanofibers
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
XML: View XML
Baez, Carlos; Considine, John; Rowlands, Robert 2014. Influence of drying restraint on physical and mechanical properties of nanofibrillated cellulose films. Cellulose Volume 21, 2014; pp. 347-356.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility