Polycarbonate (PC) is a transparent, impact resistant polymer that provides protection against breakage or intrusion. The mechanical toughness of PC is reported to be associated with the molecular motion of main chain molecules. The molecular motion is present upon exposure to impact and can therefore provide efficient dissipation of impact energy. PC has found wide usages in military and commercial applications. This thesis investigates processing and characterization of transparent PC/carbon nanotube (CNT) composite films. The reinforcing capability and efficiency of CNTs in nanocomposites have been studied intensely world-wide due to their exceptional mechanical properties. Not only do they provide stiffness and strength, but they also have been reported to impart fracture toughness when dispersed in polymer matrices. As cracks develop in nanocomposites, CNTs serve as the bridging nanofibrils that effectively retard crack propagation. In some cases, CNTs act as obstacles that obstruct the crack propagation paths, thus increasing the energy needed to be dissipated for further crack opening. This research deals with two important issues in multi-walled carbon nanotube (MWNT)-based composites that are seemingly trade-offs – dispersion of high-loading MWNTs and maintenance of optical transparency. Higher loading of MWNTs is desired for increased reinforcing effects; however, it is limited by the difficulties in achieving uniform dispersion in the polymer resin due to increased viscosity and the tendency of MWNTs to aggregate. At the same time, only a small addition of MWNTs (less than 1 wt.%) makes the resin turn dark, which defeats the advantage of the transparency that should otherwise be retained by PC. PC/MWNT composite films (up to 0.15 wt.% MWNT) were fabricated using a solvent-based film casting method. Several optimization schemes were adopted to determine the most suitable solvent and the concentrations of PC/MWNT in the solvent. Solvent-induced PC crystallization, which was evidenced by milky tinting in the produced films, was minimized by identifying and optimizing the process parameters, namely, PC/MWNT/solvent solution viscosity, casting temperature, and film thickness. Design of experiments technique was used to determine the combination of optimal parameters. / A Thesis submitted to the Department of Industrial Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Spring Semester, 2007. / April 12, 2007. / Multi-Wall Carbon Nanotube, Transparent Film, Polycarbonate / Includes bibliographical references. / Young-Bin Park, Professor Directing Thesis; Ben Wang, Committee Member; Zhiyong Liang, Committee Member; Okenwa Okoli, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_182055 |
| Contributors | Chin, Yuan-Chen (Craig) (authoraut), Park, Young-Bin (professor directing thesis), Wang, Ben (committee member), Liang, Zhiyong (committee member), Okoli, Okenwa (committee member), Department of Industrial and Manufacturing Engineering (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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