Forward recoil spectrometry study of the diffusion of PMDA/ODA-based poly(amic ethyl esters)

Stoffel, Nancy; Chandra, Sweta; Krämer, Edward J.; Volksen, Willi; Russell, Thomas P.

doi:10.1016/s0032-3861(97)00044-x

Cited by 11 publications

(6 citation statements)

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“…There is an inverse relationship between the imide fraction of the base layer and the amount of interdiffusion measured with FRES. 1 Hence these data for G c are consistent with the hypothesis that G c is strongly correlated to the width of the interface. The G c that results when a layer is spun cast onto a fully imidized base layer (f…”

Section: Resultssupporting

confidence: 85%

“…The similarity in the profile shapes for the two polyimide precursors is consistent with earlier observations that small differences in the structure of the spun-on tracer layer (including variations in the leaving group or isomeric structure of the polyimide precursor) do not result in measurable differences in the interpenetration behavior. 1 The bulk of the interdiffusion between the polyimide precursor, dPAA or dPAE, and the PI occurs during the spin-casting/drying process. Using FRES, Tead et al 14 showed that the diffusion process is facilitated by the presence of solvent.…”

Section: Resultsmentioning

confidence: 99%

“…In our previous work 1 the interdiffusion of polyimide layers was examined with forward recoil spectrometry (FRES). It was determined that this technique does not have sufficient resolution to probe the narrow interfaces formed when a polyimide precursor is deposited upon a base layer with imide fraction >0.7.…”

Section: Introductionmentioning

confidence: 99%

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High-Resolution Profiling of the Polyimide−Polyimide Interface

Stoffel¹,

Dai²,

Krämer³

et al. 1996

Macromolecules

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Dynamic secondary ion mass spectrometry (SIMS), nuclear reaction analysis, and neutron reflectometry were used to profile polyimide-polyimide interfaces. For interfaces between two layers of poly(4,4′-oxydiphenylene-pyromellitimide) (PMDA-ODA) polyimide it was determined that the interfacial fracture energy Gc and the interfacial width depended primarily upon the imide fraction, f, of the base layer. For f <0.9, there was a sharp interface between the deuterium-labeled poly(amic acid ethyl ester) (dPAE) and the base layer with a long low volume fraction tail of dPAE penetrating into the base layer. The volume fraction of the penetrant was limited by the imide fraction of the base layer and approached zero for f > 0.9. The PMDA-ODA/PMDA-ODA interface formed with a fully imidized base layer was ∼30 Å in width, whereas that formed when f ) 0.9 was ∼80 Å in width. The interface formed during the spin-casting process did not broaden significantly after annealing at 400°C. We also investigated the interface between a more flexible thermoplastic polyimide poly(4,4′-oxydiphenylene-oxydiphthalimide) (ODPA-ODA) and a fully imidized PMDA-ODA layer. The shape of the ODPA-ODA/PMDA-ODA interface was found to depend upon annealing temperature. Unannealed samples and samples annealed at 350°C could be fit with an error function, and the interfacial width was ∼50 Å. Samples annealed at 400 and 450°C were best fit by a fairly sharp interfacial profile with ODPA-ODA tails proceeding into the PMDA-ODA layer. The volume fraction of the ODPA-ODA in the PMDA-ODA depended upon the annealing temperature Tann. The Gc of the ODPA-ODA/PMDA-ODA interface appears limited by the solubility of ODPA-ODA in PMDA-ODA.

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Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 99%

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High-Resolution Profiling of the Polyimide−Polyimide Interface

Stoffel¹,

Dai²,

Krämer³

et al. 1996

Macromolecules

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“…The response of Kapton HN to alkali hydrolysis by a 1 M KOH solution is completely different from that of Kapton H. Stoffel et al 15, 16 and Lee et al 4–6 demonstrated that the depth of the hydrolysed surface layer for Kapton H grew linearly with treatment time. We also followed the hydrolysis of Kapton H film by depth profiling using TOF‐SIMS, as shown in Fig 7.…”

Section: Resultsmentioning

confidence: 99%

“…This wet chemical treatment improved adhesion between polyimide and various polymers such as polyimide, epoxy as well as metals. Later, Stoffel et al 15, 16 studied this chemical modification on Kapton H and Upilex S polyimide films by employing Rutherford backscattering and forward recoil spectrometry. The influence of a potassium carbonate base on the hydrolysis of polyimide has also been studied 17.…”

Section: Introductionmentioning

confidence: 99%

Surface modification studies of Kapton^® HN polyimide films

Huang

Bhangale

Moran

et al. 2003

Polymer International

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Surface imide hydrolysis of Kapton HN polyimide films in a 1 M KOH aqueous solution was studied using dynamic contact angle measurements, X‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS). The surface energy of Kapton HN increased quickly upon KOH treatment due to the formation of polar polyamate. Prolonged treatment led to a jump in surface energy that we ascribe to the onset of etching causing increased surface roughness. Potassium depth profiles of treated Kapton HN samples measured by XPS and TOF‐SIMS demonstrated that during the first 10 minutes of 1 M KOH treatment the modification depth increased rapidly. Thereafter the thickness of the modified layer no longer increased. For Kapton H films, however, the development of etching was much slower and a steady increase in modification depth was observed even after long treatment times. The different behaviours between Kapton HN and Kapton H films in alkali solutions are analysed and discussed. Copyright © 2003 Society of Chemical Industry

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Synergistic Effect of a Palladium‐on‐Carbon/Platinum‐on‐Carbon Mixed Catalyst in Hydrogen/Deuterium Exchange Reactions of Alkyl‐Substituted Aromatic Compounds

Ito¹,

Watahiki²,

Maesawa³

et al. 2006

Adv Synth Catal

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Abstract:We have found a synergistic effect in the H-D exchange reaction of alkyl-substituted aromatic compounds using the Pd/C-Pt/C-D 2 O-H 2 system. This system would lead to fully H-D exchange results even on the sterically hindered sites which were only low-deuterium incorporated by Pd/C or Pt/C independently. Since the reaction was general for a variety of aromatic compounds, it could be applied to the deuteration of dianiline derivatives as raw materials for polyimides.Keywords: catalysis; deuteration; palladium; platinum; synergistic effect Deuterium-labeled compounds have been extremely useful in many different branches of science including analysis of drug metabolism, investigation of reaction mechanisms and kinetics etc.[1] Recently, deuterium-labeled polymers were recognized as new materials for wave guides in optical communication systems due to their transparency in the infrared wavelength region.[2]The post-synthetic incorporation of deuterium by the hydrogen isotope exchange reaction using D 2 O, which is the cheapest deuterium compound, as a deuterium source is a cost-wise attractive method. A number of H-D exchange procedures of aromatic compounds in D 2 O have been reported, for example, the H-D exchange reaction catalyzed by acids, [3] bases [4] or transition metals (Ir, [5] Ru, [6] Rh, [7] Pt [8] and Pd [9] ) and supercritical [10] or microwave enhancement [6,8f] exchange reactions. However, many such methods involve contraindications with specific functionalities, low deuterium efficiency and/or the requirement of a vast amount of catalyst and special apparatus.We have recently reported a characteristic H-D exchange reaction catalyzed by Pd/C or Pt/C using D 2 O in the presence of a small amount of H 2 gas, [11] that is, Pd/C catalyzed the H-D exchange reaction at inactive alkyl chains [11b] and Pt/C catalyzed it at aromatic rings [11e] efficiently. We also applied the reaction to the stepwise deuteration of alkyl-substituted aromatic compounds using Pt/C and Pd/C and obtained high deuterium efficiency. Meanwhile, when we tried to examine the deuteration using Pd/C and Pt/C at the same time, and a surprisingly high deuterium efficiency by a synergistic effect was observed. Herein, we report the efficient deuterium incorporation into alkyl-substituted aromatic compounds by synergistic effect of the Pd/C-Pt/C-D 2 O-H 2 system. First, we examined the deuteration of 5-phenylvaleric acid using Pd/C and Pt/C independently or mixed them as a catalyst and Table 1 summarizes a comparison of the deuterium efficiencies. 5-Phenylvaleric acid and 10 % Pd/C (10 wt %) in D 2 O at 180 8C under a small amount of hydrogen in a sealed tube for 24 h leads to high deuterium efficiency on the aromatic ring and alkyl chain, except for the C3 (ortho) position (entry 1). On the other hand, using 5 % Pt/C (20 wt %) as a catalyst leads to high deuterium efficiency on the aromatic ring, except for the C3 (ortho) position (entry 3). The low deuterium efficiency of the C3 position is probably caused by steric hindran...

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Forward recoil spectrometry study of the diffusion of PMDA/ODA-based poly(amic ethyl esters)

Cited by 11 publications

References 4 publications

High-Resolution Profiling of the Polyimide−Polyimide Interface

High-Resolution Profiling of the Polyimide−Polyimide Interface

Surface modification studies of Kapton^® HN polyimide films

Synergistic Effect of a Palladium‐on‐Carbon/Platinum‐on‐Carbon Mixed Catalyst in Hydrogen/Deuterium Exchange Reactions of Alkyl‐Substituted Aromatic Compounds

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Forward recoil spectrometry study of the diffusion of PMDA/ODA-based poly(amic ethyl esters)

Cited by 11 publications

References 4 publications

High-Resolution Profiling of the Polyimide−Polyimide Interface

High-Resolution Profiling of the Polyimide−Polyimide Interface

Surface modification studies of Kapton® HN polyimide films

Synergistic Effect of a Palladium‐on‐Carbon/Platinum‐on‐Carbon Mixed Catalyst in Hydrogen/Deuterium Exchange Reactions of Alkyl‐Substituted Aromatic Compounds

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Surface modification studies of Kapton^® HN polyimide films