The objective of this research project is to synthesize two and three component polyimide by solution polymerization technique. Further, to synthesize four-component pendent polyimides by attaching the zirconium complex to the three component (3,4' -ODA/ODPA/MADA) polyimide backbones in presence of DCC to give the atomic oxygen resistant polyamic acid and polyimide. The synthesized zirconium complex pendent polyamic acid was characterized by Thin Layer Chromatography (TLC) to investigate its formation. TLC results indicated that no free zirconium complex remain in the polymer solution. Woven glass and carbon fibres were impregnated with the polyamic acid in the ratio of 40:60 of the resin : fibre forming a prepreg. Using the standard processing conditions for polyamic acids (resembling NASA's LARC-IA polyimide), the prepregs were cured to fabricate single and four ply glass and carbon fibre reinforced composites of both parent (without pendent groups) and pendent polymers using autoclave machine at the University of Delaware to obtain well consolidated laminates. The molding cycle, as adopted, yielded laminates of 2-, 3- and 4- component polyimides. Mechanical testing were then carried out on these laminates. The mechanical properties, such as tensile strength, flexural strength, DMA, Izod impact strength, and hardness were measured and compared for two, three and four component polyimide composites. In glass fibre composite laminates, the Zr pendent polyimide has higher glass transition temperature, Tg, storage modulus, E\ and thermal stability than the parent polyimides as observed from DMA results. The tensile strength and hardness of the four component glass fibre composites was higher compared to the parent polyimides. This could be due to strong adhesion of Zr pendent group to glass fibre. Thus, this composite could have potential use in the applications where adhesion of the polymer to any glass substrate is required. The two component carbon fibre composites showed better xiv performance in tensile, flexural and impact strength as well as hardness compared to three and four component polyimide composites. The composites were also observed under the Optical Microscope and Scanning Electron Microscope (SEM) after the mechanical tests to study the effects of adhesion of polymer resin to the fiber reinforcement. Our hypothesis that the zirconium pendant group is responsible for the strong adhesion to glass was supported by these mechanical tests.
Library of Congress Subject Headings
Polyimides--Synthesis; Polyimides--Analysis; Zirconium compounds; Carbon composites
Department, Program, or Center
School of Chemistry and Materials Science (COS)
Nangia, Sangeeta, "Zr-pendent polyimide carbon/glass composites and their property comparisons with the corresponding non pendent polyimide composites" (2002). Thesis. Rochester Institute of Technology. Accessed from
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