Synthesis and Characterization of Modified Nanoclay for Polymer Nanocomposite Applications

Date
2017
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Abstract
Polymer nanocomposites (PNCs) have several advantages, such as excellent mechanical properties, lightweight, durability, easy process-ability and low cost due to nanofiller high surface area. The main objective of this PhD thesis is to develop modified nanoclays for PNC, particularly high density polyethylene (HDPE) PNCs with enhanced mechanical and thermal properties. This has been accomplished by modifying the nanofiller constituents and optimizing the fabrication and processing methods. Different techniques for modifications were used depending on the end-use applications of the nanocomposites. These techniques were built upon a comprehensive understanding of the nanofiller structure and the modification type for PNC applications. The synthesized nanofiller and the nanocomposite’s final properties were investigated, and mechanical, thermal and rheological performance were characterized for PNC. In this PhD thesis, different nanoclays were synthesized and used as nanofiller in high density polyethylene. The resulting nanocomposites showed improvement in some mechanical and thermal properties. Different strategies were employed: (1) modification of nanofillers, (2) synthesis of novel nanofillers, (3) use of hybrid filler systems, and (4) and optimization of the processing conditions. For nanofiller modification, we performed chemical treatment of nanoclay and synthesis of hybrid clay/CNT. Functionalized clay was synthesized using silane coupling agents to take advantage of high thermal resistance of the silane coupling agents over traditionally used surfactants. The silane modified clay was further functionalized in a second reaction. The main objective of these strategies was to improve the affinity of polymer with clay, and increase interlayer space, and consequently, to increase dispersion of nanofillers in the host polymer to enhance PNC properties. Utilizing a secondary filler to further enhance the desired properties was another strategy. This was accomplished by synthesizing in situ hybrid CNT/clay nanofiller; that is, CNT was synthesized using CVD process directly on the clay silicate surface. Finally, we optimized PNC production methods (e.g., melt mixing, catalyst synthesis and clay functionalization). The aim of the last two strategies was to obtain improved mechanical and physical properties for the nanocomposite, and it is well known that nanocomposite structure can be used to control the final PNC properties.
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Keywords
Chemistry, Chemistry--Polymer, Engineering--Chemical, Materials Science, Plastics Technology
Citation
Asgari, M. (2017). Synthesis and Characterization of Modified Nanoclay for Polymer Nanocomposite Applications (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27950