Synthesis and characterization of side-chain liquid crystalline polycarbosilanes with siloxane spacer

Komuro, Katsuhiko; Kawakami, Yusuke

doi:10.1007/s002890050517

Cited by 10 publications

(5 citation statements)

References 1 publication

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“…Meanwhile, poly(siloxane)s, consisting of [SiRR‘O] repeating units, a class of unique organic−inorganic hybrid polymers, have been extensively used as one of the most important thermally stable rubbery and insulating materials. Especially, poly(dimethylsiloxane)s have been widely used as silicone oil, silicone rubber, main chain for liquid crystalline polymers, and polymer support for metallocene catalysts by taking advantage of their highly flexible structure and high thermal stability.…”

Section: Introductionmentioning

confidence: 99%

Tris(pentafluorophenyl)borane as a Superior Catalyst in the Synthesis of Optically Active SiO-Containing Polymers

Zhou

Kawakami

2005

Macromolecules

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Tris(pentafluorophenyl)borane was found to be an effective catalyst in the synthesis of optically pure and completely diisotactic phenyl- and naphthyl-substituted poly(siloxane)s by the reaction between (R,R)-1,3-dimethyl-1,3-diphenyl {or di(1-naphthyl)}-1,3-disiloxanediol and 1,1,3,3-tetramethyl-1,3-disiloxane, 1,1,6,6-tetramethyl-1,6-disilahexane, or 1,4-bis(dimethylsilyl)benzene under mild reaction conditions. The optically active disloxane units in the produced polymers had better controlled chemical and stereoregular structures than those obtained from the bis(silanol)s and bis(dimethylamino)dimethylsilane. Homopolymerization of the starting bis(silanol) could be almost completely suppressed. Effects of the structure of the starting bis(silane)s on the yield, molecular weight, optical activity, and thermal properties of the resulting SiOSi-containing polymers were studied.

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Section: Introductionmentioning

confidence: 99%

Tris(pentafluorophenyl)borane as a Superior Catalyst in the Synthesis of Optically Active SiO-Containing Polymers

Zhou

Kawakami

2005

Macromolecules

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“…Because the Karstedt catalyst was reported to be effective for ring‐opening polymerization of various silacyclobutane derivatives, four‐membered ring‐opening polymerization of OBMSB was first examined by heating a toluene solution of OBMSB in the presence of 0.1 mol % of Karstedt catalyst (platinum vinylsiloxane complex) at 70 °C (Scheme ). The polymerization proceeded smoothly and the monomer was quantitatively consumed within 1 h, which was checked by 1 H NMR measurement of the crude reaction mixture.…”

Section: Resultsmentioning

confidence: 99%

Polymerization of an epoxy‐containing silacyclobutane and its application to networked polymer synthesis

Matsumoto

Goto

Nagao

et al. 2014

J. Polym. Sci. Part A: Polym. Chem.

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Polymerization of a silacyclobutane having an epoxy moiety and its application to networked polymer synthesis were examined. Four-membered ring-opening polymerization of silacyclobutane having a 3,4-epoxybutyl group on the silicon atom (OBMSB) was achieved by using a platinum vinyldisiloxane complex with keeping the epoxy ring unchanged. Copolymerization of 1,1-diethylsilacyclobutane (DESB) with OBMSB by using the same catalyst effectively gave the corresponding copolymers [poly(DESB-co-OBMSB)]. Thermal properties of the polyOBMSB, polyDESB, and poly(DESB-co-OBMSB) were investigated by DSC and TGA. Cast films of the obtained polymers with 1naphthylmethylmethyl-p-hydroxyphenylsulfonium hexafluor-oantimonate, a small amount of thermally latent acid generator were prepared. Heating the films at 80 C for 2 h gave crosslinked networked polycarbosilanes through cationic ring-opening of the epoxy moieties. Thermal and mechanical properties of the networked polymers were investigated by TGA, DSC, and tensile strength measurements.

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“…Among them, polycarbosilanes with higher chemical stability than polysiloxanes can act as a main chain component for liquid crystalline polymer similar to polysiloxanes [2,3]. In addition, introduction of a ¼ -conjugated aromatic ring as a carbon moiety can give rise to ¾ -¼ conjugation, which may result in unique electrical and optical properties, such as high hole mobility and sharp ultraviolet emission [4,5].…”

Section: Introductionmentioning

confidence: 99%

Catalytic synthesis and characterization of stereoregular and optically active polycarbosilanes

Kawakami¹,

Takeyama²,

Shinke³

et al. 2004

Designed Monomers and Polymers

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Abstract-Stereoregular and optically active polycarbosilanes were synthesized by polyaddition of optically active allylsilane and propargylsilane, and ring-opening polymerization of optically pure benzosilacyclobutene. Polyaddition of allylsilane gave an isotactic polymer, but chirality at the silicon center was lost in the polymer and the polymer became optically inactive. Propargylsilane, having a triple bond, can maintain double-bond and single-bond carbons attached to silicon atom even after polyaddition by hydrosilylation, and the formed polymer showed optical activity. Catalytic ringopening polymerization of an optically pure benzosilacyclobutene gave an optically active polymer with high stereoregularity with well-controlled molecular weight by using triethylsilane as a chaintransfer agent.

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Synthesis and characterization of side-chain liquid crystalline polycarbosilanes with siloxane spacer

Cited by 10 publications

References 1 publication

Tris(pentafluorophenyl)borane as a Superior Catalyst in the Synthesis of Optically Active SiO-Containing Polymers

Tris(pentafluorophenyl)borane as a Superior Catalyst in the Synthesis of Optically Active SiO-Containing Polymers

Polymerization of an epoxy‐containing silacyclobutane and its application to networked polymer synthesis

Catalytic synthesis and characterization of stereoregular and optically active polycarbosilanes

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