Wei Wang

Abstract

The objective of this thesis is to synthesize functionalized zirconium complex pendent polyamic acids and polyimides, then compare their characteristics, e.g. thermal properties, atomic oxygen resistance, and film properties (adhesion, flexibility, and solvent resistance). Towards this end, five different zirconium complexes were attached to the polyamic acid, which is based on 3,4'-oxydianiline (3,4'-0DA), 4,4'-oxydiphthalic anhydride (ODPA), and mellitic dianhydride (MADA), in the presence of dicyclohexylcarbodiimide (DCC). The resulting zirconium complex pendent polyamic acids and the parent polyamic acid were cast onto glass substrates, then thermally imidized by heating at 100C, 200C, and 300C for one hour each. The synthesized zirconium complex pendent polyamic acids and polyimides were characterized by Thin Layer Chromatography (TLC), Fourier Transform Infrared (FT-IR), Proton Nuclear Magnetic Resonance (H1 NMR), Gel Permeation Chromatography (GPC), Light Scattering test (LS), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electronic Microscopy (SEM), Refractive index, and Contact Angle Measurement to investigate their adhesive properties. TLC results indicate that no free zirconium complexes remain in the polymer solutions. Spectroscopic results support the conclusion that the structures obtained are consistent with the proposed ones. Both the GPC results and LS results indicate that a moderate degree of polymerization occurred (average degree of polymerization ca. 1 00), and the weight average molecular weight of the pendent polymers is higher than the parent polymer. Decomposition temperatures of pendent polyimides are slightly lower than that of the parent polyimide, but all are above 500C, which means that they possess very high thermal stability. The SEM results and visual observation indicate that the atomic oxygen erosion of the zirconium pendent polyimide films leaves a white surface reside, which is due primarily to the formation of zirconium dioxide. The generation of a uniform zirconium dioxide layer protects the original material from atomic oxygen erosion. The zirconium pendent polyimides have higher glass transition temperatures, Tg, than the parent polyimide. All of the imidized films passed the solvent resistance test, by remaining flexible following immersion in acetone, methyl ethyl ketone, toluene, dimethylacetamide, and chloroform for 30 minutes followed by a fingernail crease. Two-layer thick films cracked upon imidization.

Library of Congress Subject Headings

Polymides--Synthesis; Polyamides--Analysis; Zirconium compounds

Publication Date

12-1-2000

Document Type

Thesis

Department, Program, or Center

School of Chemistry and Materials Science (COS)

Advisor

Illingsworth, Marvin

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 W364 2000

Campus

RIT – Main Campus

Download

Share

COinS