• 한국염색가공학회:학술대회논문집
• /
• 한국염색가공학회 2006년도 임시총회 및 추계학술발표회
• /
• pp.213-215
• /
• 2006

• 한국광과학회:학술대회논문집
• /
• 한국광과학회 2002년도 정기총회 및 제9회 광과학 학술심포지움 논문초록
• /
• pp.33-33
• /
• 2002

• Bulletin of the Korean Chemical Society
• /
• 제28권4호
• /
• pp.698-700
• /
• 2007

• Bulletin of the Korean Chemical Society
• /
• 제25권6호
• /
• pp.777-778
• /
• 2004

• 대한화학회지
• /
• 제39권11호
• /
• pp.878-880
• /
• 1995

• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 1999년도 제2회 총회 및 춘계학술발표회
• /
• pp.27-27
• /
• 1999

• 대한치과기공학회지
• /
• 제2권1호
• /
• pp.21-24
• /
• 1980

This experiment was intended to obtain a prefect casting body the same as the original wax patterns by melting metal into the opening of the ring. The investment ring was dried to the temperature between 600 and 700, when the wax pattern would be completely melted to leave an empty mould made in the ring. The main point to studied was the investing process for perfect casting body. This process was experimented on several important factors: the size and spatulation of investment particles, purity of wax patterns, investing time after the completion of model, and investing temperature. The results obtained from the above experiment were as follows: A desirable cast body with no fissure or pore would be mode by investing with smaller particles in the first time and with larger onces in the second, both at the temperature between 180.

• Bulletin of the Korean Chemical Society
• /
• 제20권10호
• /
• pp.1195-1199
• /
• 1999

2-(2,4,5-Trimethoxyphenyl)-4-methylene-1,3-dioxolane (1b), 2-(2,4,6-trimethoxyphenyl)-4-methylene-1,3-di-oxolane (2b), and 2-(3,4,5-trimethoxyphenyl)-4-methylene-1,3-dioxolane (3b) were prepared and polymerized with boron trifluoride. Boron trifluoride catalyzed reaction proceeded via mainly ring-opening polymerization and cyclization reaction to yield poly(keto ether) and 3(2H)-dihydrofuranone. The yields of polymer and cyclized product exhibited a dependency on the position of the methoxy substituents in the benzene ring of 2-phenyl-4-methylene-1,3-dioxolane derivatives. Electrophilic attack of methylene or oxygen atom on 4-meth-ylene-1,3-dioxolane ring were suggested for the polymerization and cyclization.

• Bulletin of the Korean Chemical Society
• /
• 제32권spc8호
• /
• pp.3074-3080
• /
• 2011

We synthesized three novel poly(norbornene bisimide)s by ring opening metathesis polymerization (ROMP) and subsequent hydrogenation. Their thermal, mechanical and optical properties were investigated with TGA, DMA, UV-Vis spectrometer, and optical reflectometer. The new polymers showed high glass transition temperatures over $260^{\circ}C$ and good thermal stability with 5% wt-loss temperature higher than $390^{\circ}C$. When solvent casted, they yielded optically transparent and dimensionally stable films with a relatively low coefficient of thermal expansion of about 50 ppm $K^{-1}$. Therefore, the bisimide moieties substantially enhanced thermal and dimensional stabilities, as compared with normal ROMP-prepared polynorbornene films. Though the water uptake was increased to 0.6 wt-%, this water uptake is still considerably lower than that for polyethersulfones (1.4 wt-%) or polyimides (2.0 wt-%). Hence, the new poly(norbornene bisimide)s may become attractive candidates for flexible substrates of optoelectronic devices such as displays and photovoltaic solar cells.

• 공업화학
• /
• 제9권7호
• /
• pp.1018-1022
• /
• 1998

본 연구에서는 테트라하이드로퓨란(THF)의 개환중합반응에 의해 변형된 12-몰리브도인산의 특성 및 촉매 반응성을 살펴보았다. 기상 에탄올 전화반응에서 THF에 의해 변형된 12-몰리브도인산은 모산 촉매보다 매우 우수한 전환율 및 생성물 수율을 보였다. 변형된 12-몰리브도인산의 증가된 반응성은 변형된 헤테로폴리음이온의 구조적 유연성과 약화된 수소결합에 기인하는 것으로 판단된다. THF는 양성자 또는 결정수를 매개로 헤테로폴리산과 상호작용을 하는 것으로 나타났는데, 결정수를 중심으로 한 THF와 헤테로폴리음이온간의 상호작용이 변형된 12-몰리브도인산의 촉매 활성을 결정하는 주된 요인이었다.