Plasma and beam facility atomic oxygen erosion of a transition metal complex

Illingsworth, Marvin L.; Banks, Bruce A.; Smith, James W.; Jayne, D. T.; Garlick, R. G.; Rutledge, Sharon K.; Groh, Kim K. de

doi:10.1007/bf01570179

Cited by 9 publications

(9 citation statements)

References 5 publications

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“…A pristine sapphire disk was located adjacent to a film of organically-wrapped zirconium coordination complex, bis(N,N 1disalicylidene-1,2-phenylenediaminato)zirconium(IV), Zr(dsp) 2 , on glass in an oxygen beam facility. Following AO exposure, X-ray photoelectron spectroscopy (XPS) confirmed that the complex was being transformed into zirconium dioxide without deposition of volatile zirconium-containing contaminants onto the sapphire [14]. However, one limitation was encountered.…”

Section: Introductionmentioning

confidence: 99%

Pendent Polyimides using Mellitic Acid Dianhydride. I. An Atomic Oxygen-resistant, Pendent 4,4′-ODA/PMDA/MADA Co-polyimide Containing Zirconium

Wagner

Dai

Stapleton

et al. 2006

High Performance Polymers

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The goal of this research is to increase the metal-organic concentration in Kapton-like polyimides (PIs) to achieve increased atomic oxygen (AO) resistance while retaining desirable film properties. Co-polyamic acid (PAA) precursors were prepared using a novel polymer building block, mellitic acid dianhydride (MADA), to provide sites for pendent group attachment. Attachment of an amino group-functionalized zirconium complex to the co-PAA precursors was facilitated by a stoichiometric amount of dicyclohexylcarbodiimide. The viscous solutions which resulted were characterized by thin layer chromatography (TLC), viscosity, and gel permeation chromatography (GPC), or treated with excess poor solvent to precipitate powder samples, or cast onto glass slides and heated to produce imidized films. Powder samples were dissolved in deuterated solvent for proton nuclear magnetic resonance analysis, or characterized by thermogravimetric analysis and differential scanning calorimetry. Film samples were characterized by Fourier transform infrared and by scanning electron microscopy (SEM) before and after exposure to atomic oxygen in a plasma asher. The spectroscopic data are consistent with the expected amic acid and imide, pendent and non-pendent structures. TLC, viscosity and GPC results confirm the polymeric nature of the pendent and non-pendent co-PAA precursors, with inherent viscosities (<0)of 0.76 and 0.65 and weight average molecular weights (Mw) estimated to be 61 000 and 138 000 Dalton, respectively. As expected, visual and SEM inspections of pendent and non-pendent co-PI films reveal extensive surface roughening upon exposure to AO, with the former developing a white surface layer known from model compound studies to be predominantly zirconium dioxide. Additional reports describing the effects of polymer structure and pendent group concentration on film properties and AO resistance are in preparation.

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Section: Introductionmentioning

confidence: 99%

Pendent Polyimides using Mellitic Acid Dianhydride. I. An Atomic Oxygen-resistant, Pendent 4,4′-ODA/PMDA/MADA Co-polyimide Containing Zirconium

Wagner

Dai

Stapleton

et al. 2006

High Performance Polymers

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“…Incorporation of zirconium-containing components onto PI matrices is being investigated as a means to enhance their AO resistance and extend performance lifetime in LEO. We contend that in situ formation of zirconium dioxide upon AO exposure, as previously demonstrated [47], will provide superior protection to underlying polymer than AO protective coatings. Such coatings invariably have surface manufacturing defects which allows AO undercutting to occur at these locations [45,48] and have no self-repairing capability if compromised by impact.…”

Section: Introductionmentioning

confidence: 68%

“…Use of a polysiloxane-PI blend to generate a protective silicon oxide layer in LEO caused a volatile contaminant to be deposited on adjacent surfaces [49]. This problem was not observed upon ground-based AO exposure of the Zr-containing component being used here [47].…”

Section: Introductionmentioning

confidence: 94%

“…The strengthening shoulder at approximately 1650 cm 21 , observed as the mole percentages of MADA and Zr-pendent groups are increased, is consistent with an amide pendent group attachment. Furthermore, upon exceeding temperatures of 520 3 C for high mole percent of Zr pendent and 560 3 C for PENDENT POLYIMIDES USING MELLITIC ACID DIANHYDRIDE 757 low mole percentage of Zr pendent, the weight of TGA residue (mostly zirconium dioxide [47]) is roughly proportional to the mole percentage of zirconium pendent in each formulation. Table 3 includes the initial weight loss and decomposition temperatures for these polymers as well.…”

Section: Pendent Polyimides Using Mellitic Acid Dianhydride 755mentioning

confidence: 99%

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Pendent Polyimides using Mellitic Acid Dianhydride. IV. Effect of Increased Zirconium-Pendent Group Content on Polymer Properties

Chow

Cheng

Dai

et al. 2008

High Performance Polymers

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For co-polyimides (PIs) of mellitic acid dianhydride, 1,3-aminophenoxybenzene and 4,4′-oxydiphthalic anhydride, Zr-pendent group content could be increased to 50% (mol) improving atomic oxygen (AO) resistance while retaining good film properties. Spectral data are consistent with expected structures. Intrinsic viscosities of 0.54—0.60 dL g—1 and average molecular weights of 111 000—122 000 g mol— 1 estimated from gel permeation chromatography confirm the polymeric nature of co-polyamic acid precursors. Nuclear magnetic resonance integrations and amounts of thermogravimetric analysis residue verify pendent group concentrations. Increasing Zr-pendent group concentration from 10 to 50% (mol) caused glass transition temperatures to increase (198—245 °C), decomposition temperatures to decrease (518—455 °C), and the number of film layers able to be fabricated prior to crack formation to decrease (10 to 8). These numbers of layers were much higher than those for other PIs with comparable Zr-pendent group concentrations. Increased pendent group concentration caused the amount of protective oxide layer formed upon AO exposure to increase.

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“…Wet films were then cast and thermally imidized 50. The in situ generation of a protective metal oxide layer upon land‐based AO exposure was considered proof of concept 50, 51. However, a significant decrease in film quality was observed even at relatively low additive concentrations.…”

Section: Introductionmentioning

confidence: 99%

Pendent polyimides using mellitic acid dianhydride. III. The effect of pendent group functionality on polymer properties

Illingsworth

Wang

McCarney

et al. 2009

J of Applied Polymer Sci

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Methyl, methoxy, and nitrile (cyano) functional groups were incorporated into the metal-organic pendent group of a co-polyamic acid, co-PAA [(3,4 0 -ODA/ ODPA) 0.9 (3,4 0 -ODA/{MADA-p-Zr(adsp)(Rdsp)}) 0.1 ], in various locations to investigate their effects on polymer chain interactions and film quality. Proton nuclear magnetic resonance and gel permeation chromatography (GPC) performed on solutions of these products were consistent with the expected 10% (mol) functionalized pendent polymeric structures. Thermogravimetric analysis performed on ether-precipitated samples revealed little functional group effect on imidization temperature (decreases of 5-8 C), but showed a somewhat-greater effect on decomposition temperature (decreases of 6 C for the 3-methoxy derivative to 28 C for the methyl derivative). Differential scanning calorimetry performed on imidized powder samples showed that glass transition temperatures increased with the addition of the functional groups from 2 C for the methyl derivative to 19 C for the 3-methoxy derivative. Imidized films were solvent resistant, transparent, and flexible, with the nitrile derivative least susceptible to crack formation. Light scattering results revealed that the nitrile derivative had the lowest second virial coefficient of the functional groups tested and formed aggregates at room temperature in NMP with n ¼ 2, thus rationalizing its superior film forming properties. Results of contact angle measurements and atomic oxygen exposure of functionalized pendent co-PI films are included.

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Plasma and beam facility atomic oxygen erosion of a transition metal complex

Cited by 9 publications

References 5 publications

Pendent Polyimides using Mellitic Acid Dianhydride. I. An Atomic Oxygen-resistant, Pendent 4,4′-ODA/PMDA/MADA Co-polyimide Containing Zirconium

Pendent Polyimides using Mellitic Acid Dianhydride. I. An Atomic Oxygen-resistant, Pendent 4,4′-ODA/PMDA/MADA Co-polyimide Containing Zirconium

Pendent Polyimides using Mellitic Acid Dianhydride. IV. Effect of Increased Zirconium-Pendent Group Content on Polymer Properties

Pendent polyimides using mellitic acid dianhydride. III. The effect of pendent group functionality on polymer properties

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