Analysis of the effect of processing conditions on physical properties of thermally set cellulose hydrogels

Type of content
Journal Article
Thesis discipline
Degree name
Publisher
MDPI AG
Journal Title
Journal ISSN
Volume Title
Language
English
Date
2019
Authors
Huber T
Feast S
Dimartino S
Cen W
Fee C
Abstract

Cellulose-based hydrogels were prepared by dissolving cellulose in aqueous sodium hydroxide (NaOH)/urea solutions and casting it into complex shapes by the use of sacrificial templates followed by thermal gelation of the solution. Both the gelling temperatures used (40-80 °C), as well as the method of heating by either induction in the form of a water bath and hot press or radiation by microwaves could be shown to have a significant effect on the compressive strength and modulus of the prepared hydrogels. Lower gelling temperatures and shorter heating times were found to result in stronger and stiffer gels. Both the effect of physical cross-linking via the introduction of additional non-dissolving cellulosic material, as well as chemical cross-linking by the introduction of epichlorohydrin (ECH), and a combination of both applied during the gelation process could be shown to affect both the mechanical properties and microstructure of the hydrogels. The added cellulose acts as a physical-cross-linking agent strengthening the hydrogen-bond network as well as a reinforcing phase improving the mechanical properties. However, chemical cross-linking of an unreinforced gel leads to unfavourable bonding and cellulose network formation, resulting in drastically increased pore sizes and reduced mechanical properties. In both cases, chemical cross-linking leads to larger internal pores.

Description
Citation
Huber T, Feast S, Dimartino S, Cen W, Fee C (2019). Analysis of the effect of processing conditions on physical properties of thermally set cellulose hydrogels. Materials. 12(7). 1066-1066.
Keywords
cellulose, hydrogel, physical cross-linking, chemical cross-linking
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
Field of Research::09 - Engineering::0912 - Materials Engineering
Field of Research::03 - Chemical Sciences::0306 - Physical Chemistry (incl. Structural)
Field of Research::12 - Built Environment and Design::1203 - Design Practice and Management::120302 - Design Innovation
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© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).