• Bulletin of the Korean Chemical Society
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• 제20권6호
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• pp.677-682
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• 1999

Conjugated polycarbosilanes with diacetylene and aromatic groups of thiophene or phenylene simultaneously present in the polymer backbone such as poly[[1,4-bis(thiophenyl)buta-1,3-diyne]-alt-(dimethylsilane)], poly[[1,4-bis(thiophenyl)buta-1,3-diyne]-alt-(diphenylsilane)], poly[[1,4-bis(phenyl)buta-1,3-diyne]-alt-(dimethylsilane)],and poly[[1,4-bis(phenyl)buta-1,3-diyne]-alt-(diphenylsilane)] have been prepared. The characteristic C=C stretching frequencies appear at 2177-2179㎝-1 in the IR spectra of the polymers. The molecular weights of these polymers were detemined by GPC. All of these materials are soluble in organic solvents such as THF and chloroform, and thermally stable up to 200℃ in general without any weight loss under nitrogen. The prepared materials in THF solvent show a maximum absorption peak in the range of 334-356 nm with a molar absorptivity of 10³∼10ⁿ(n=5)L/(cm·mol) in the UV-visible absorption spectra. A maximum emission peak in the range of 403-550 nm is also observed in the fluorescence emission spectra. Both absorption and emission spectra strongly indicate that the obtained polycarbosilanes contain the new conjugated systems along the polymer main chain.

• 한국고분자학회지:고분자과학과기술
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• 제8권3호
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• pp.282-292
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• 1997

• Bulletin of the Korean Chemical Society
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• 제27권6호
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• pp.869-874
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• 2006

We have carried out the Glaser oxidative coupling polymerizations of diethynyldiphenylsilane, diethynylmethylphenylsilane,diethynylmethyloctylsilane, and 1,2-diethynyl-1,1,2,2-tetramethyldisilane to afford polycarbosilanes containing diethynyl and organosilane groups in the main chain, such as poly(diethynyldiphenylsilane), poly(diethynylmethylphenylsilane), poly(diethynylmethyloctylsilane), and poly(1,2-diethynyl-1,1,2,2-tetramethyldisilane), respectively. These obtained materials are almost insoluble in common organic solvents such as $CHCl_3$ and THF probably due to the presence of a rigid rod diacetylene group along the polymer main chain. Therefore, the polymers were characterized using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic $C \equiv C$ stretching frequencies appear at 2147-2154 $cm ^{-1}$, in particular. The polymers in the solid state exhibit that the strong maximum excitation peaks appear at 260-283 nm and the strong maximum fluorescence emission bands at 367-412 nm, especially. Thermogravimetric analysis of the materials shows that about 55-68% of the initial polymer weights remain at 400 ${^{\circ}C}$ in nitrogen.

• Bulletin of the Korean Chemical Society
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• 제24권4호
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• pp.484-488
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• 2003

Polycarbosilanes containing diacetylene and organosilacyclic groups, such as poly(1,1-diethynyl-1-silacyclopent-3-ene), poly(1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene), and poly(1,1-diethynyl-1- silacyclobutane), were synthesized by the Glaser oxidative coupling polymerization reactions of 1,1-diethynyl-1-silacyclopent-3-ene, 1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene, and 1,1-diethynyl-1-silacyclobutane, respectively. These materials are almost insoluble in usual organic solvents such as $CHCl_3$ and THF. The polymers were characterized by using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic C≡C stretching frequencies appear at 2146-2170 $cm^{-1}$, in particular. The polymers in the solid state show that the strong maximum excitation peaks appear at 255-257 nm and the strong maximum fluorescence emission bands at 401-402 nm. About 71-87% of the initial polymer weights remain at 400 ℃ in nitrogen according to thermogravimetric analysis.

• 한국세라믹학회지
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• 제42권8호
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• pp.593-598
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• 2005

Polycarbosilane was synthesized by the Kumada rearrangement of polydimethylsilane in the presence of zeolite (ZSM-5) as a catalyst at $350^{\circ}C$. The prepared polycarbosilane had very low molecular weight ($M_w=500$), so that it was not suitable to fabricate SiC fiber by melt spinning. Further polymerization of PCS was conducted around $400^{\circ}C$ to obtain spinnable polycarbosilane. After polymerization, the polycarbosilanes were isolated by distillation according to the molecular weight distributions. The PCS with a controlled molecular weight distribution was spun into continuous polycarbosilane green fibers. The PCS green fiber was successfully transformed into silicon oxycarbide fiber. The room temperature strength of the SiC fiber was around 1.5 - 1.8 GPa. The oxidation behavior and the tensile strength after oxidation were also evaluated.

• 대한화학회지
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• 제43권4호
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• pp.393-400
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• 1999

Hyperbranched polymer를 이용한 나뭇가지꼴 카보실란 거대분자를 합성하였다 Hyperbranched polymer의 영세대 화합물의 합성은 $HSiMe_{3-n}$$(CH_2CH=CH_2)_n$(n=2; $AB_2$,3;$AB_3$형)의 수소화규소첨가반응 방법을 이용하여 합성하였다. Hyperbranched polymer $AB_2$와 $AB_3$형 고분자 화합물은 수소화규소첨가반응과 알켄첨가반응에 의해 Gn+1형 나뭇가지꼴 거대분자로 성장하였다. Gn+2P세대 화합물은 $HSiMeCl_2$와의 수소화규소첨가반응 방법에 의해 모든 가지가 동일형 화합물을 형성하지 못했다. Gn과 Gn+1형 고분자 화합물은 9-BBN과의 반응과 반응생성물의 산화반응에 의해서 polysilol을 형성하였다. 반응의 정도는 NMR에 의해서 확인할 수 있었다.