Improved thermal stability of cellulose nanofibrils using low-concentration alkaline pretreatment

Hansol Lee; Jaya Sundaram; Lu Zhu; Yiping Zhao; Sudhagar Mani

doi:10.1016/j.carbpol.2017.08.119

Improved thermal stability of cellulose nanofibrils using low-concentration alkaline pretreatment

Carbohydr Polym. 2018 Feb 1:181:506-513. doi: 10.1016/j.carbpol.2017.08.119. Epub 2017 Sep 7.

Authors

Hansol Lee¹, Jaya Sundaram², Lu Zhu³, Yiping Zhao⁴, Sudhagar Mani⁵

Affiliations

¹ College of Engineering, University of Georgia, Driftmier Engineering Center, 597 DW Brooks Drive, Athens, GA, 30602, USA. Electronic address: hl23429@uga.edu.
² College of Engineering, University of Georgia, Driftmier Engineering Center, 597 DW Brooks Drive, Athens, GA, 30602, USA. Electronic address: jsundaram3@gmail.com.
³ College of Engineering, University of Georgia, Driftmier Engineering Center, 597 DW Brooks Drive, Athens, GA, 30602, USA. Electronic address: zhulu@uga.edu.
⁴ Department of Physics and Astronomy, University of Georgia, Athens, GA, 30602, USA. Electronic address: zhaoy@physast.uga.edu.
⁵ College of Engineering, University of Georgia, Driftmier Engineering Center, 597 DW Brooks Drive, Athens, GA, 30602, USA. Electronic address: smani@engr.uga.edu.

PMID: 29254001
DOI: 10.1016/j.carbpol.2017.08.119

Abstract

The thermal stability of cellulose nanofibrils (CNFs) can be improved by converting cellulose crystalline structure to cellulose II using an alkaline treatment method. The conventional method requires around 20wt.% NaOH solutions and causes the cellulose interdigitation and aggregation, making CNFs production difficult. The objective of this study is to develop a new pretreatment method using a low-concentration alkaline solution to produce well-dispersed CNFs with improved thermal stability. CNFs with 90nm diameter were successfully prepared by treating cellulose powder with 2wt.% NaOH solution below 0°C, followed by homogenization through a French pressure cell press. The CNFs had relatively high thermal stability with the mean onset and maximum thermal decomposition temperature of 305°C and 343°C, respectively, compared with the CNFs prepared without the NaOH pretreatment (283°C and 310°C). The increased thermal stability can create new opportunities for the development of CNF-based bio-composites and electronics.

Keywords: Cellulose II; Cellulose nanofibrils; French pressure cell press; NaOH treatment; Thermal stability.