Huixiong Dai

Abstract

Poly(amic acid)s (PAAs) of pyromellitic dianhydride (PMDA), 4, 4'-oxydianiline (ODA), and mellitic dianhydride (MDA), PAA(PMDA-ODA-MDA), and PAAs of 4,4'- oxydiphthalic anhydride (ODPA), ODA, and MDA, PAA(ODPA-ODA-MDA), were synthesized by solution polycondensation with different anhydrides ratios. Their zirconium containing polyimides, which are atomic oxygen resistant materials with potential applications on the International Space Station, were prepared by introducing a mixed ligand zirconium complex (4-amino-N,N'-disalicylidene-l,2-phenylenediaminato) (N,N,-disalicylidene-l,2-phenylenediaminato)zirconium(IV), Zr(adsp)(dsp), onto the polymer chain as a pendant group. The attachment was accomplished by the nucleophilic substitution between the amino group in the complex and the anhydride carbonyl group in the polymer chain formed by the dehydration of adjacent carboxylic acid groups of MDA components with dicyclohexycarbodiimide (DCC). The attachment reaction was followed by the thermal imidization of the poly(amic acid) precursors. The Zr(adsp)(dsp) was chosen for its atomic oxygen resistance. The synthesized poly(amic acid)s were characterized as follows. Proton Nuclear Magnetic Resonance ( 'H NMR ) revealed the polymer backbone structures and the presence of unremoved NMP solvent. Gel Permeation Chromatography (GPC) indicated that average molecular weights of Zr pendent and nonpendent PAAs were in the range of 60,000 and 650,000. In Thermogravimetric Analysis (TGA) the Zr pendent PAAs showed a slight lower thermal stability than the nonpendent PAAs. The imidization processing of the poly(amic acid)s to polyimides was studied by Fourier Transform Infrared (FTIR), which showed that the imidization started at 100 C and finished aparently at 300 C. Multilayer 10 mol% Zr complex pendent PMDA-ODA-MDA polyimides films were made. The SEM of Zr pendent polyimide after oxygen plasma etching shows that

Library of Congress Subject Headings

Polyimides--Synthesis; Polyimides--Analysis; Zirconium compounds

Publication Date

8-1-1997

Document Type

Thesis

Department, Program, or Center

School of Chemistry and Materials Science (COS)

Advisor

Illingsworth, M.

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TP1180.P66 D34 1997

Campus

RIT – Main Campus

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