Hydrolytically stable fluorocarbon ether bibenzoxazole polymers

Evers, Robert C.; Abraham, Tonson; Burkett, Jerald L.

doi:10.1002/pol.1981.170190218

Cited by 5 publications

(4 citation statements)

References 3 publications

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“…The delayed decoupling spectrum reveals that the carbon at 139.5 ppm is nonprotonated while the carbons at 129. 6 and 52 ppm are protonated. A small peak at 63 ppm which was hidden under the broad protonated carbon resonance at 52 ppm is revealed in the delayed decoupling experiment.…”

Section: )mentioning

confidence: 99%

“…The acetylene group has been used as a cure site for many different polymer classes including polyimides,1 poly (aryl ether sulfones),2 polyphenylenes,3 polyesters,4 poly(phenyl-os-triazines) ,5 poly(perfIuoroalkylene ether benzoxazoles), 6 and poly(phenylquinoxalines).7 One of the advantages of this cure site is that no volatile byproducts are evolved during its cure. This can result in voidfree polymer structures.…”

Section: Introductionmentioning

confidence: 99%

“…Figure6. Delayed decoupling experiments of acetyleneterminated oligomer labeled at the diary 1 carbonyl and C-2 ethynyl positions.…”

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confidence: 99%

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Acetylene-terminated polyimide cure studies using carbon-13 magic-angle spinning NMR on isotopically labeled samples

Swanson¹,

Fleming²,

Hofer³

1992

Macromolecules

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The solid-state cure mechanisms of an acetylene-terminated polyisoimide have been studied using solid-state l3C cross-polarixation magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy on samples which had been selectively labeled using 13C labeled precursors. The polymer backbone was labeled at sites which were expected to be involved in the cure chemistry: the benzophenone carbonyl carbon, the isoimidelimide carboxyl carbon, the C-1 (quaternary acetylene) ethynyl carbon, or the C-2 (terminal acetylene) ethynyl carbon. After preparing and subsequently curing the selectively labeled and unlabeled (control) resins identically, difference spectroscopy techniques were used to subtract the resonances due to the natural abundance nuclei, thereby resulting in spectra which were due to the selective label alone. Combining this technique with delayed decoupling experiments in which one allows the 13C nuclei that are coupled to protons ('H) to relax, those resonances which are protonated and nonprotonated were identified. The results were correlated with model and related compounds. The carbonyl function remained unchanged in the cured product. The isoimidelimide carboxyl carbons underwent an isomerization reaction to produce the expected imide structure. The solid-state ethynyl cure products were found to contain aromatic structures, condensed polycyclic aromatic structures, backbone addition and bridge structures. Steric factors and population densities of reactive sites in the polymer could influence the ratio of these products.

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Section: )mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Acetylene-terminated polyimide cure studies using carbon-13 magic-angle spinning NMR on isotopically labeled samples

Swanson¹,

Fleming²,

Hofer³

1992

Macromolecules

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“…Acetylene‐ or phenylacetylene‐terminated resins can be thermally cured without giving off volatiles. Acetylene groups have been used as crosslinking reaction sites in aromatic polyimides,1, 2 poly(ether ketone sulfone)s,3, 4 polyphenylquinoxalines,5 poly(phenyl‐ as ‐triazine)s,6 Schiff base polymers,7 poly(perfluoroalkylene ether benzoxazole)s,8 poly(phenylquinozaline)s9 and polyphenylenes 10. Resins terminated with acetylene or phenylacetylene have a long shelf life and their cured products have excellent solvent resistance and favorable combination of physical and mechanical properties at high temperature.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and thermal cure of diphenyl ethers terminated with acetylene and phenylacetylene

Wang

Zhang

et al. 2006

Polymer International

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Two kinds of novel compounds, diphenylacetylene diphenyl ether (DPADPE) and diacetylene diphenyl ether (DADPE), were prepared and polymerized under heating. Raman, DSC and 13 C CP/MAS NMR analyses were used for studying the polymerization reaction. DPADPE and DADPE have melting points at 190 and 79 • C, with exothermic peaks of the DSC curves at 375 and 215 • C for curing, respectively. Raman and 13 C CP/MAS NMR spectra show that DPADPE could be cured at a temperature higher than 300 • C and DADPE at a lower temperature of higher than 150 • C. The kinetic parameters for the thermal crosslinking reactions were obtained by the Ozawa method and the results show that the apparent activation energy is 152 kJ mol −1 for DPADPE and 109 kJ mol −1 for DADPE. An ene-yne Straus product appears in the cured DADPE, whereas this product has not been identified in the cured DPADPE. The cured DPADPE and DADPE demonstrate good thermal and thermo-oxidative stability.

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Influence of carbon black type and concentration upon thermooxidation of the amorphous phase in high and low density polyethylenes

Drǎgan

1986

Acta Polymerica

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Thermooxidation in solid and molten state of HDPE and LDPE loaded with different types of carbon black is studied by DSC measurements on mill rolled specimens and tensile test on compression moulded specimens by considering the isothermal induction times a t 210 to 25OOC and the elongation a t break a t room temperature, respectively. The terms of morphology stability and compatibility between P E and carbon black species are defined on the basis of recently established topoenergetic principles according t o which the notions have meaning only in respect t o a transformation process revealed in a measuring system which includes the standard experimental conditions. The universal representation allows to determine by iteration the threshold temperature To = (240 f 10) K below which the thermooxidation of the amorphous phase is practically inhibited. This value fairly corresponds to the glass transition temperature like for other polymers and transformation processes studied on topoenergetic basis. Der EinfluP von Art und Konzentration des RuPes auf die Thermooxidation der amorphen Phase in Polyethylenen hoher und niedriger DichteDie Thermooxidation von mit verschiedenen RuBtypen gefullten HDPE und LDPE im festen und geschmolzenen Zustand wurde mittels DSC-Messungen an gewalzten Proben und durch Zugprufungen an gepreBten Proben untersucht, indem die isothermen Induktionspcrioden im Bereich von 210 bis 250°C sowie die Bruchdehnungen bei Raumtemperatur bestimmt wurden. Die Begriffe der morphologischen Stabilitat und der Vertraglichkeit zwischen PE und RUB werden auf der Basis von in neueren Arbeiten abgeleiteten topoenergetischen Prinzipien definiert. Danach haben diese Begriffe einen Sinn nur in bezug auf den TransformationsprozeB in einem bestimmten MelJsystem, wozu auch die experimentellen Standardbedingungen rnit gehoren. Die universelle Darstellung erlaubt die Bestimmung einer Grenztemperatur T o = (240 & 10) K, unterhalb der praktisch keine Thermooxidation der amorphen Phase erfolgt. Dieser Wert stimmt ziemlich gut rnit der Glasubergangstemperatur uberein, wie das auch bei anderen Polymeren und Transforrnationsprozessen bei der Untersuchung auf topoenergetischer Basis gefunden wurde. Bnuxnue muna u Eonyenmpayuu caMu na mepwoomcnenue awopg5nod 6a3bc nonusmunena ebacolcoii u nu3lcoiL nhomnocmu

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Hydrolytically stable fluorocarbon ether bibenzoxazole polymers

Cited by 5 publications

References 3 publications

Acetylene-terminated polyimide cure studies using carbon-13 magic-angle spinning NMR on isotopically labeled samples

Acetylene-terminated polyimide cure studies using carbon-13 magic-angle spinning NMR on isotopically labeled samples

Synthesis and thermal cure of diphenyl ethers terminated with acetylene and phenylacetylene

Influence of carbon black type and concentration upon thermooxidation of the amorphous phase in high and low density polyethylenes

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