• Bulletin of the Korean Chemical Society
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• 제23권10호
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• pp.1377-1378
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• 2002

• Bulletin of the Korean Chemical Society
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• 제22권9호
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• pp.939-940
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• 2001

• Bulletin of the Korean Chemical Society
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• 제18권12호
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• pp.1245-1247
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• 1997

• Bulletin of the Korean Chemical Society
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• 제20권12호
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• pp.1384-1386
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• 1999

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.366-369
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• 2003

The vertical fountain plating system with the point contact has been used in semiconductor industry. But the plating shape in the opening of photoresist becomes gradated shape, because bubbles from the wafer surface are difficult to escape from the deep openings, vias. So, we designed the tilted electrode ring contact to get uniform bump height on all over the wafer and evaluated the film uniformity by SEM and $\alpha$-step. A photoresist was coated to a thickness of $60{\mu}m$ and vias were patterned by a contact aligner After via opening, solder layer was electroplated using the fountain plating system and the tilted electrode ring contact system. In $\alpha$-step measurement, film uniformities in the fountain plating system and the tilted electrode ring contact system were ${\pm}16%,\;{\pm}3.7%$ respectively. In this study, we could get high uniformity bumps by the tilted electrode ring contact system. So, tilted electrode ring contact system is expected to improve workability and yield in module process.

• Bulletin of the Korean Chemical Society
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• 제20권12호
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• pp.1433-1436
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• 1999

The 2-(2,4-dimethoxyphenyl)-4-MDO (2) underwent polymerization with ring opening as well as cyclization reaction in the presence of various cationic catalysts such as boron trifluoride, trifluoromethanesulfonic acid, p-toluenesulfonic acid, hydrochloric acid and trifluoroacetic acid. They afforded a mixture of the ring-opened poly(keto ether) and 3(2H)-dihydrofuranone derivative. Both the methylene group and oxygen atom of 1,3-dioxolane ring were participated in the reaction with cationic catalyst. The contents of the polymer and cyclization product were variable according to the acid strength of the cationic catalysts.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.793-795
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• 1998

• 공업화학
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• 제2권1호
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• pp.64-69
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• 1991

1, 2-Dithiolane 기를 갖는 lipid를 합성하여 vesicle 을 형성시킨 다음 이것을 ring opening polymerization 하여 고분자화된 vesicle을 합성하였다. 중합반응의 반응속도를 UV를 이용하여 측정한 결과, 반응속도가 1차반응 속도식을 만족하였으며 반응속도 상수값은 $3.84{\times}10^{-2}min^{-1}$이었다. 또한 sucrose를 이용한 투과도 실험에서 고분자화된 vesicle의 투과도는 $4.7{\times}10^{-8}cm\;hr^{-1}$이었으며 이 값은 고분자화되지 않은 경우보다 1.5배 낮은 것이다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.199-199
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• 2006

Microwave-irradiation has become a common heat source in organic chemistry in the last decade. In recent years, polymer chemists also discovered the advances of microwave heating that include fast and efficient heating as well as the homogeneous heat profile and the easy access to pressurized reaction conditions. In this contribution, we report our investigations on the cationic ring-opening polymerization of 2-oxazolines that lead to a tremendous acceleration from several days to several minutes polymerization time. In addition, the optimized microwave-assisted polymerization procedure was applied for the preparation of libraries of diblock and triblock copolymers that were used for the determination of structure-property relationships in poly(2-oxazoline)s.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.104-105
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• 2006

We succeeded the synthesis of new functional polymers by novel ring-opening addition reactions of bis(oxetane)s with diacyl chlorides, di(active ester)s, and di(carboxylic acid)s using quaternary onium salts as catalysts at appropriate conditions. Hyperbranched polyesters with many pendant hydroxy groups were also synthesized by the polyaddition of bis(oxetane)s with tricarboxylic acid, or by the self-polyadditions of $AB_2\;or\;A_2B$ type monomers containing oxetane group. The anionic ring-opening polymerization of (3-ethyl-3-hydroxymethyl)oxetane was examined using sodium tert-buthoxide to give hyperbranched poly(ether)s containing one oxetanyl group and many hydroxyl groups in the end of polymer chain.