All cellulose composites prepared in an ionic liquid.
2010-12
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
All cellulose composites prepared in an ionic liquid.
Authors
Published Date
2010-12
Publisher
Type
Thesis or Dissertation
Abstract
The overall goal of this project was to investigate all-cellulose composites prepared in a “green” solvent – ionic liquid. The approach was to partially dissolve cellulose and subsequently convert it into a matrix domain embedding the reinforcement domain – the undissolved cellulose. Microcrystalline cellulose (MCC) was partially dissolved in 1-N-Butyl-3-methylimidazolium chloride (BMIMCl) ionic liquid. The dissolved portion of cellulose was precipitated by adding water, and the gels obtained were washed, dried, and pressed into films. The all-cellulose composite films were structurally characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM), while their properties were determined using tensile tests and dynamic vapor sorption (DVS) studies. XRD results verified that the crystallinity index and weight fraction of cellulose I in the composites can be controlled by controlling the soaking time and cellulose concentrations. The tensile test data revealed that the all-cellulose composite produced in this study had mean elastic moduli and strength of up to 4.4 GPa and 49 MPa, respectively, which are in the range of a randomly oriented biofiber-reinforced polymer composites. The tensile properties increased as a response to the composite density, which was found to increase as more cellulose II matrix (from increased dissolution) was present to presumably better fill the voids. This presumption was supported by SEM images of cryo-fractured surfaces. The sorption isotherms obtained from DVS studies showed a non-sigmoidal behavior at low relative humidity levels (<44%), while the equilibrium moisture content values at higher humidity levels closely correlated to the cellulose I crystallinity index of the composites. Overall, this study verified that dissolution of cellulose in ionic liquid can be controlled to control the properties of all-cellulose composites.
Description
University of Minnesota M.S. thesis. December 2010. Major: Natural resources science & management. Advisor: Dr. William Tai Yin Tze. 1 computer file (PDF); ix, 63 pages.
Related to
Replaces
License
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Zhou, Lili. (2010). All cellulose composites prepared in an ionic liquid.. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/103595.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.