Structure analysis of a soluble polysiloxane-block-polyimide and kinetic analysis of the solution imidization of the relevant polyamic acid

Furukawa, Nobuyuki; Yuasa, Masatoshi; Kimura, Yoshiharu

doi:10.1002/(sici)1099-0518(19980930)36:13<2237::aid-pola10>3.0.co;2-b

Cited by 16 publications

(4 citation statements)

References 14 publications

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“…20 nm) for block copolyimides (polysiloxane-b-polyimide) with a roughly similar molecular weight of the PSX phase. 37,38 This reflects the compact structure and tough ordering of PSX particles formed by the sol-gel process and corresponds well to the previously determined 9 elongation at break (5-20%) of these materials, which is significantly smaller than value reported in the literature 39 (ca. 90%) for linear block copolymers with similar composition.…”

Section: Resultssupporting

confidence: 89%

Mobility, Structure, and Domain Size in Polyimide−Poly(dimethylsiloxane) Networks Studied by Solid-State NMR Spectroscopy

et al. 2002

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Dynamics, structure, and domain size in polyimide-poly(dimethylsiloxane) networks (PI-PSX) with various compositions were investigated by solid-state NMR spectroscopy. 29 Si and 13 C MAS NMR spectroscopy revealed the presence of PSX chains in two motional states, and their relative content was estimated. The overall mobility as well as local motions was studied by 1D and 2D 1 H wide-line spectroscopy. 2D WISE spectra proved large differences in molecular mobility of PSX and PI chains. High mobility of PSX is not imparted to rigid PI, and the interfacial region is located in the PSX phase. This region corresponds to the immobilized PSX chains at the surface of PSX domains, which link PI chains. The spherical morphology and domain sizes at the nanometer scale were determined from analysis of spin diffusion processes. Molecular mechanics and dynamics calculations were performed to design PSX domains at the atomic level. Correlation of the structure and morphology with mechanical and thermal properties is discussed.

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Section: Resultssupporting

confidence: 89%

Mobility, Structure, and Domain Size in Polyimide−Poly(dimethylsiloxane) Networks Studied by Solid-State NMR Spectroscopy

et al. 2002

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“…The yield of furfural amine can reach 85.7 % when Ni:Mo = 2:1 (Tab. 2, entries 10,12,15). Therefore, by adjusting the reaction conditions, the Ni-Mo/ZrO 2 catalyst showed the best catalytic performance, obtaining the highest yield of 96. a) Reaction conditions: furfuraloxime, 55.5 g, 0.5 mol; 6 % NH 3 in methanol (NH 3 added to methanol at 0-5 °C and concentration calculated as percentage by mass), 600 mL; catalyst, 6 g; temperature, 70 °C; reaction time, 4 h; stirring speed, 1000 rpm.…”

Section: Reductive Amination With Different Metal Catalystsmentioning

confidence: 95%

“…The special structure of heterocyclic primary amines can lead to better coordination properties and higher quality. Therefore, heterocyclic primary amines are gradually being developed and applied [10,11].…”

Section: Introductionmentioning

confidence: 99%

Production of Heterocyclic Primary Amines from Heterocyclic Aldehydes on Ni‐Mo/ZrO₂

et al. 2022

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Ni-Mo/ZrO 2 catalysts with Ni-Mo loadings of 10 wt % were prepared by a sol-gel method on a ZrO 2 support and subsequently applied in the simple reductive amination of heterocyclic aldehydes. Among the various catalysts prepared, Ni-Mo/ZrO 2 catalysts with Ni:Mo = 2:1 exhibited the highest metal dispersion and the smallest Ni particle size. The results showed that the catalyst has good catalytic performance, in which the yield of furfurylamine can reach 96.6 %. Initially, oximes were synthesized from the corresponding aldehydes and hydroxylamine hydrochloride, and then heterocyclic primary amines were synthesized by simple hydroreductive amination of the oximes with a 12 % methanolic solution of NH 3 in the presence of an Ni-Mo/ZrO 2 catalyst. The methanolic solution of NH 3 was found to be more effective in inhibiting the formation of secondary and tertiary amines.

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“…These disadvantages make conventional polyimides extremely difficult to process and severely limit their commercial uses. Various attempts have been made to overcome these deficiencies, including the use of noncoplanar or alicyclic monomers7–10 and the introduction of flexible segments into the polymer backbone 11–13. Methods for overcoming these deficiencies include reducing chain crystallinity, intermolecular charge‐transfer, and electronic polarization interactions.…”

Section: Introductionmentioning

confidence: 99%

Introduction to special section: Disparities in rheumatic diseases

Yelin¹,

Katz²

2007

Arthritis & Rheumatism

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Two series of aromatic polyimides containing various‐sized alkyl side groups were synthesized by thermal imidization of the poly(amic acid)s prepared from the polyaddition of benzophenonetetracarboxylic dianhydride and hexafluoro‐isopropylidene bis(phthalic anhydride) with 4,4′‐methylenedianiline, 4,4′‐methylene‐bis(2,6‐dimethylaniline), 4,4′‐methylene‐bis(2,6‐diethylaniline), and 4,4′‐methylene‐bis(2,6‐diisopropylaniline). The extent to which alkyl substitutes affect the thermal properties of polyimides was examined by differential scanning calorimetry, thermomechanical analyzer, and thermogravimetric analysis techniques. The analytical results demonstrated that the incorporation of alkyl moieties causes a moderate increase in the coefficient of thermal expansion and a slight decrease in thermal stability. Notably, all polymers had a decomposition temperature exceeding 500°C. The glass transition temperature increases markedly when hydrogen atoms at ortho positions on aniline rings are replaced with methyl groups, but decreases with growing alkyl side group size. The dielectric measurements show that the polymer possessing a large alkyl side group would have the lower dielectric value. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4672–4678, 2006

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Structure analysis of a soluble polysiloxane-block-polyimide and kinetic analysis of the solution imidization of the relevant polyamic acid

Cited by 16 publications

References 14 publications

Mobility, Structure, and Domain Size in Polyimide−Poly(dimethylsiloxane) Networks Studied by Solid-State NMR Spectroscopy

Mobility, Structure, and Domain Size in Polyimide−Poly(dimethylsiloxane) Networks Studied by Solid-State NMR Spectroscopy

Production of Heterocyclic Primary Amines from Heterocyclic Aldehydes on Ni‐Mo/ZrO₂

Introduction to special section: Disparities in rheumatic diseases

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Structure analysis of a soluble polysiloxane-block-polyimide and kinetic analysis of the solution imidization of the relevant polyamic acid

Cited by 16 publications

References 14 publications

Mobility, Structure, and Domain Size in Polyimide−Poly(dimethylsiloxane) Networks Studied by Solid-State NMR Spectroscopy

Mobility, Structure, and Domain Size in Polyimide−Poly(dimethylsiloxane) Networks Studied by Solid-State NMR Spectroscopy

Production of Heterocyclic Primary Amines from Heterocyclic Aldehydes on Ni‐Mo/ZrO2

Introduction to special section: Disparities in rheumatic diseases

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Production of Heterocyclic Primary Amines from Heterocyclic Aldehydes on Ni‐Mo/ZrO₂