In this thesis a new generation of layered silicates was used for modification of PMMA with the goal to reach a maximum in stiffness-toughness-balance without sacrificing tensile strength and processability. Additionally, the micromechanical effect of these novel nanofillers has been evaluated using fracture surface analysis and structure-property-relationships have been established. To highlight the better performance of the novel nanofiller compared to conventionally used layered silicates, a commercially available system based on surface-modified Bentone has been used as benchmark material and the properties of its nanocomposites have also been analyzed in detail. Finally, a deep understanding about the extent of influence of various filler properties on nanocomposite properties was generated. The newly developed PMMA nanocomposites based on layered silicates of the second generation show a unique stiffness-toughness balance. The huge lateral extension and the resulting low particle densities in combination with high aspect ratio and high intrinsic stiffness make the layered silicates a high performance nanofiller. The conventionally used layered silicates lead only to an increase of stiffness at the cost of strength and fracture toughness reflecting the results from literature. In terms of fracture toughness, the conventionally nanofillers are not effective as their lateral extension is too small to promote any additional toughening mechanism. On the contrary, the layered silicates of the second generation lead to the occurrence of additional energy dissipating mechanisms like crack pinning or crack deflection and this to a significant increase of fracture toughness.
|School:||Universitaet Bayreuth (Germany)|
|Source:||DAI-C 81/1(E), Dissertation Abstracts International|
|Subjects:||Materials science, Nanotechnology, Polymer chemistry|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be