• 한국추진공학회지
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• 제18권5호
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• pp.35-42
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• 2014

본 연구에서는 시차주사열량계시험, 반응열시험, 접착전단시험을 통해 자가치료제의 열분석 특성과 접착 특성을 평가하였다. 자가치료제는 DCPD와 ENB의 혼합비에 따라 D1E0, D3E1, D1E1, D1E3, D0E1을 고려하였다. 촉매는 Grubbs' catalyst를 자가치료제의 종류에 따라 0.1 wt%에서 1.5 wt%까지 적용하였다. DCPD의 경우는 촉매 양이 많을수록 중합반응이 빠르고 안정화된 접착강도가 높아지지만 많은 양의 촉매가 요구된다. ENB의 경우 촉매와의 반응성이 우수하여 적은 양의 촉매로도 빠른 중합반응을 얻을 수 있지만 반응열이 높게 나타난다. DCPD와 ENB의 혼합비를 변화시키면 자가치료제의 열분석 특성 및 접착 특성을 조절할 수 있으며 본 연구에서 고려한 자가치료제 중 D3E1가 최대접착강도, 최대접착강도에 도달하는 시간, 안정화된 접착강도, 반응열 측면에서 자가치료제로 가장 유리함을 알 수 있다.

• 폴리머
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• 제37권3호
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• pp.356-361
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• 2013

본 연구에서는 5-ethylidene-2-norbornene(ENB)과 가교제가 혼합된 ENB 자가치료제에 melamine-urea-formaldehyde로 둘러싸인 마이크로캡슐을 제조하였다. 이때 자가치료제에는 빨간 색소를 첨가하여 관찰이 용이하도록 하였다. 마이크로캡슐의 열적 저항성과 캡슐의 크기 및 분포 그리고 형상을 관찰한 결과 우수한 캡슐이 제조된 것을 확인하였으며, 자가치료제에 빨간 색소의 첨가가 캡슐의 형성에 영향을 주지 않았다. 또한 마이크로캡슐과 Grubbs 촉매를 에폭시 코팅 층에 분산시킨 다음 이에 손상을 가하여 크랙을 유발하고 그것을 광학현미경으로 관찰한 결과, 크랙에 의해 캡슐이 파손되어 자가치료제가 흘러나와 크랙 면을 채우고 촉매와 반응하는 것을 알 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.435-436
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• 2006

This study focused on the introduction of the self healing technique for polymeric composites and evaluated the healing efficiency by the use of the interlaminar toughness fracture test. The DCPD (dicyclopentadiene) and ENB (5-ethylidene-2-norbornene) were used for the healing agent and the Grubbs' catalyst was used for the catalyst. According to the results, healing efficiency was found to be 37.9%, 22.3%, 26.3%, 22.8%, 30.8%, 30.8%, 33.0%, 33.4% for mode II fraction of 0%, 20%, 35%, 50%, 65%, 80%, 90%, 100%, respectively.

• 약학회지
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• 제48권1호
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• pp.88-92
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• 2004

In this study; a series of 2',4'-doubly branched carbocyclic nucleosides (8,9,10) were synthesized from simple acyclic ketone derivative as starting material. The installation of the 4'-quaternary carbon needed was carried out using a 〔3,3〕-sigmatropic rearrangement. In addition, the introduction of a methyl group in the 2'-position was accomplished by Grig-nard reaction. Bis-vinyl was successfully cyclized using a Grubbs' catalyst II. The natural bases (adenine, cytosine, uracil) were efficiently coupled with the use of a Pd(0) catalyst. Although all the synthesized compounds were assayed against several viruses, only cytosine analogue 9 showed weak antiviral viral activity (EC$_{50}$=45.4 $\mu$M) against CoxB3 virus.s.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1812-1816
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• 2004

The stereoselective synthesis 4′,6′-dually branched carbocyclic nucleosides was accomplished in this study. The introduction of a methyl group in the 6′$({\alpha})$-position was accomplished by Felkin-Anh controlled alkylation. The construction of the required 4′$({\alpha})$-quaternary carbon was carried out using a [3,3]-sigmatropic rearrangement. Bis-vinyl 6 was successfully cyclized using a Grubbs' catalyst II. The natural bases (adenine, cytosine) were efficiently coupled using a Pd(0) catalyst. When the synthesized compounds were examined for their activity against several viruses such as the HIV-1, HSV-1, HSV-2 and HCMV, the cytosine analogue 13 exhibited good antiviral activity against the HCMV.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.262-265
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• 2004

This study focused on the introduction of the self-healing technique for polymeric composites and evaluated the healing efficiency through the interlainar fracture toughness tests. The DCPD and ENB were used for a healing agent and the Grubbs' catalyst as a catalyst. The healing efficiency was evaluated by the use of mode I and the mode n fracture toughnesses. According to the results, the DCPD-ENB mixture with a suitable ratio revealed better healing efficiency than DCPD only.

• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1520-1524
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• 2005

This paper describes the racemic and stereoselective synthetic route for a novel 4'$\alpha$-phenyl and 6'$\alpha$-methyl doubly branched carbocyclic nucleosides from an acyclic 2-hydroxy acetophenone. The installation of phenyl group at the 4'-position of carbocyclic nucleoside was successfully accomplished via a sequential [3,3]-sigmatropic rearrangement. The stereoselective introduction of a methyl group in the 6'$\alpha$-position was accomplished by Felkin-Anh controlled alkylation. Bis-vinyl 11 compound was successfully cyclized using a Grubbs’ catalyst II to desired carbocycles. The natural bases (adenine and cytosine) were efficiently coupled using a Pd(0) catalyst. Although all the synthesized compounds were examined for their activity against several viruses such as HIV-1, HSV-1, HSV-2 and HCMV, only cytosine analogues 17 exhibited weak antiviral activity against HCMV.

• 약학회지
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• 제49권1호
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• pp.20-24
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• 2005

The synthesis of 4',5'-doubly branched carbocyclic nucleosides was accomplished in this study. The selective methylation in the 5'-position was made by Felkin-Anh controlled Grignard addition. The construction of the required 4'-quaternary carbon was carried out by using a [3,3]-sigmatropic rearrangement. Bis-vinyl 6 was successfully cyclized using a Grubbs' catalyst II. The natural pyrimidine bases (cytosine, uracil, thymine) were efficiently coupled using a Pd(0) catalyst. When the synthesized compounds were examined for their activity against several viruses such as the HIV-1, HSV-1, HSV-2 and HCMV, the cytosine analogue 13 exhibited weak antiviral activity against the HCMV.

• Bulletin of the Korean Chemical Society
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• 제28권9호
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• pp.1545-1548
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• 2007

This paper discusses the racemic and stereoselective synthetic route for novel 4'α -methyl and 6'α -methyl analogues of abacavir. The quaternary carbon at the 4'-position of carbocyclic nucleoside was installed successfully via a Claisen rearrangement. The stereocontrolled construction of a methyl group in the 6'α - position was directed through the Felkin-Anh rule. A Bis-vinyl compound 9 was cyclized successfully using Grubbs' catalyst II to provide a carbocycle nucleus for the target compound. The synthesized compound 15 showed moderate anti-HIV activity (EC50 = 10.67 μM, MT-4 cell lines).

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.266-269
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• 2004

In this study, bond strengths for the self-healing agents were evaluated through the modified lap shear test in order to suggest the optimal healing conditions for the repair of polymeric composites. The healing agents of DCPD, ENB, and their mixtures were activated with Grubbs' catalysts. According to the results, the mixture of DCPD and ENB gave better opportunity than DCPD only due to the rapid acivation with catalyst in view of the economic and practical use.