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Processing and Evaluation of Multifunctional Polyimide Composite Coatings and Membranes

Longun, Jimmy
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367938249

Abstract Details

2013, PhD, University of Cincinnati, Engineering and Applied Science: Materials Science.
In this project the effect of processing variables on the structure and properties of polyimide-based composite membranes was studied. Montmorillonite-clay and substituted polyaniline-copolymer-modified-clay, SPNEAC and SPNEAC2, containing low and high Montmorillonite-clay content, respectively, were used as the filler materials. The aim of this study is to formulate multifunctional polyimide-based coatings by combining the excellent properties of polyimide such as high solvent and wear resistance, high dimensional stability, excellent thermal resistance and high modulus with the superior properties of inorganic nanoscale fillers such as rigidity, high aspect ratio and outstanding mechanical properties, among other desirable qualities. Incorporation of Montmorillonite clay into polyimide is especially very important with regard to improvement of the barrier properties of the polyimide/clay nanocomposite membrane since the high aspect ratio of clay decreases the permeability of the nanocomposite membrane by increasing the diffusion length of water and gases. This property of polyimide/clay nanocomposite enables polyimide/clay coatings to be used for corrosion prevention of aluminum alloys. The modification of Montmorillonite clay using flexible substituted-polyaniline-copolymer is aimed at improving the damping ability of the polyimide-based membranes in addition to their corrosion prevention capability. In this case, damping ability, which is correlated with impact resistance, is essential in minimizing the damage to the protective coating in the event of a strike or impact blow and thereby improving the coating lifetime. Durable, mechanically superior and corrosion resistant polyimide composites coatings and thin films were prepared using a silicone-epoxy resin and their properties were compared to those of polyimide/clay and polyimide-modified-clay. The damping ability and storage modulus of the membranes was evaluated using dynamic mechanical spectroscopy (DMS) and this result was correlated with the barrier properties of the coating which were evaluated using electrochemical impedance spectroscopy (EIS). In Electrochemical Impedance Spectroscopy (EIS) studies, the coatings impedance (electrochemical modulus) is correlated with coating resistance (impedance), which is a direct reflection of the barrier properties of the coating. Part of this work also aims to propose a mechanism of corrosion prevention by comparing electrochemical impedance spectroscopy (EIS) data to DC polarization results. Other properties of the coatings such as structure, thermal-stability and morphology were studied and correlated with corrosion performance.
Jude Iroh, Ph.D. (Committee Chair)
Stephen Clarson, Ph.D. (Committee Member)
Rodney Roseman, Ph.D. (Committee Member)
Donglu Shi, Ph.D. (Committee Member)
126 p.
Materials Science
Polyimide; Nanocomposite; Dynamic Mechanical Analysis; Corrosion Performance; Coatings; Thin Films;

Recommended Citations

Citations

  • Longun, J. (2013). Processing and Evaluation of Multifunctional Polyimide Composite Coatings and Membranes [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367938249

    APA Style (7th edition)

  • Longun, Jimmy. Processing and Evaluation of Multifunctional Polyimide Composite Coatings and Membranes. 2013. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367938249.

    MLA Style (8th edition)

  • Longun, Jimmy. "Processing and Evaluation of Multifunctional Polyimide Composite Coatings and Membranes." Doctoral dissertation, University of Cincinnati, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367938249

    Chicago Manual of Style (17th edition)

ucin1367938249
388
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