Thermotropic Liquid Crystalline Polyimides with Siloxane Linkages: Synthesis, Characterization, and Liquid Crystalline Behavior

Shoji, Yu; Ishige, Ryohei; Higashihara, Tomoya; Watanabe, Junji; Ueda, Mitsuru

doi:10.1021/ma9021828

Cited by 29 publications

(24 citation statements)

References 16 publications

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“…Unless otherwise noted, all reactions were performed under an atmosphere of dry N 2 with oven‐dried glassware and anhydrous solvents with standard dry box or vacuum line techniques. The starting products were synthesized according to the literatures (1‐(but‐3‐en‐1‐yloxy)‐4‐nitrobenzene, N‐(5‐hexenyl)phthalimide, 5‐hexenyl benzoate, 1‐[4‐hydroxy‐3‐(2‐propen‐ 1‐yl)phenyl]ethanone, 2‐propenyl benzoate, 10‐undecenyl benzoate, N‐allyl‐4‐nitroaniline, but‐3‐en‐1‐yl methyl terephthalate, 1‐bromo‐2‐(but −3‐en‐1‐yloxy)benzene, 4‐(hex‐5‐en‐1‐yloxy) benzonitrile . All other reagents and solvents were purchased were used as received from commercial sources.…”

Section: Methodsmentioning

confidence: 99%

Synthesis and Evaluation of Ruthenium 2‐Alkyl‐6‐mercaptophenolate Catalysts for Olefin Metathesis

Wang

Zhang

et al. 2019

Applied Organom Chemis

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A series of ruthenium carbene catalysts containing 2‐sulfidophenolate bidentate ligand with an ortho‐substituent next to the oxygen atom were synthesized. The molecular structure of ruthenium carbene complex containing 2‐isopropyl‐6‐sulfidophenolate ligand was confirmed through single crystal X‐ray diffraction. An oxygen atom can be found in the opposite position of the N‐heterocyclic carbene (NHC) based on the steric hindrance and strong trans‐effects of the NHC ligand. The ruthenium carbene catalyst can catalyze ring‐opening metathesis polymerization (ROMP) reaction of norbornene with high activity and Z‐selectivity and cross metathesis (CM) reactions of terminal alkenes with (Z)‐but‐2‐ene‐1,4‐diol to give Z‐olefin products (Z/E ratios, 70:30–89:11) in low yields (13%–38%). When AlCl3 was added into the CM reactions, yields (51%–88%) were considerably improved and process becomes highly selective for E‐olefin products (E/Z ratios, 79:21–96:4). Similar to other ruthenium carbene catalysts, these new complexes can tolerate different functional groups.

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Section: Methodsmentioning

confidence: 99%

Synthesis and Evaluation of Ruthenium 2‐Alkyl‐6‐mercaptophenolate Catalysts for Olefin Metathesis

Wang

Zhang

et al. 2019

Applied Organom Chemis

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“…28 The incorporation of siloxane spacer units within polyimides (1) led to significant improvements in the thermal stability (T dec 4 450 1C) of the hybrid polymer relative to traditional polyimides, and novel thermotropic liquid crystalline behavior involving polymer 1 was observed; as a result these materials have potential application as insulating components in the electronics industry. 29 In related work, Zhou and coworkers reported the synthesis of liquid crystalline polysiloxanes containing mesogenic side groups. 30 The ring-opening polymerization (ROP) of the cyclodimethylsiloxanes [Me 2 SiO] 3-6 (D 3 to D 6 ) using triflic acid and metal triflates has been reported.…”

Section: Polysiloxanes and Related Polymersmentioning

confidence: 99%

Inorganic and organometallic polymers

Rivard

2011

Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem.

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This article reviews research selected from the 2010 scientific literature involving polymers with inorganic elements as part of their backbone. HighlightsParticularly noteworthy achievements from the field of inorganic and organometallic polymers include: the synthesis of polythiophene-N-heterocyclic carbene (NHC) copolymers, 106 the further development of room temperature methods to prepare poly(alkyl/arylphosphazenes), 54 the successful ring-opening polymerization of a galla[1]ferrocenophane, 94 the controlled copolymerization of selenophenes and thiophenes to yield novel materials for solar cell applications, 81 and the discovery of polymer-based solar cells with efficiencies greater than 7%.

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“…17 In this aspect, a series of main-chain liquid-crystalline polyimides, BPDA/nSiOm, which consist of an aromatic imide BPDA mesogen and alkyl and dimethyl siloxane spacers, are interesting because some of them have been found to form both S C and S A phases. [18][19][20] One of the typical materials is the following, and the distinct structural characteristics of the S A and S C phases as examined using the wide-angle X-ray diffraction (WAXD) and Fourier transform infrared (FTIR) spectroscopy measurements for the uniaxial fiber and BPDA/3SiO4-3F film.…”

Section: Introductionmentioning

confidence: 99%

Characteristic smectic structures of main-chain liquid-crystalline polyimides driven by a microphase separation between aromatic imide mesogen and a siloxane spacer

et al. 2012

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We investigated the phase transition behavior and liquid-crystalline structure for main-chain liquidcrystalline polyimides with aromatic imide cores and alkyl and dimethyl siloxane spacers, BPDA/ 3SiO4-3F. They formed crystal, smectic C (S C ), smectic A (S A ), and isotropic phases in order of increasing temperature. The characteristic structures of the S A and S C phases were extracted with wideangle X-ray diffraction (WAXD) and Fourier transform infrared (FTIR) spectroscopy measurements. In the S C phase, the mesogenic groups were tilted by approximately 40 to the smectic layer and the unusual quasi two-dimensional structural order exists irrespective of the liquid-like packing of aromatic cores within a layer. On heating, the S C phase transformed into the S A phase with a nature of first-order transition. The resulting S A structure was also unusual. The orientational order parameter was 0.43, which was lower than 0.71 in the S C phase. This indicates that a ''de Vries''-type of smectic A is formed in which the mesogenic groups are tilted away from the optic axis, but in azimuthally random directions. The average tilt angle was estimated to be 42 . These characteristics were produced because of the strong segregation effect of the dimethyl siloxane spacer groups with a relatively larger molecular area compared to alkyl chain and aromatic imide cores.BPDA/3SiO4-3F, which has an F-substituted BPDA mesogenic unit. In this paper, we report the nature of the S A -S

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Thermotropic Liquid Crystalline Polyimides with Siloxane Linkages: Synthesis, Characterization, and Liquid Crystalline Behavior

Cited by 29 publications

References 16 publications

Synthesis and Evaluation of Ruthenium 2‐Alkyl‐6‐mercaptophenolate Catalysts for Olefin Metathesis

Synthesis and Evaluation of Ruthenium 2‐Alkyl‐6‐mercaptophenolate Catalysts for Olefin Metathesis

Inorganic and organometallic polymers

Characteristic smectic structures of main-chain liquid-crystalline polyimides driven by a microphase separation between aromatic imide mesogen and a siloxane spacer

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