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Juglone과 치환된 Dienes의 Diels-Alder반응에 관한 연구
박주훈(Joo Hoon Park),김학진(Hak Jin Kim),김준섭(Joon Seop Kim) 호서대학교 중앙도서관 1993 호서대학교 논문집 Vol.1 No.-
글루타콘산 유도체들로 부터 공액 디엔계를 갖는 2-피론유도체들을 합성하였으며, 이들 및 다른 몇가지의 디엔들의 쥬글론과의 디일스-알더반을을 여러 조건에서 수행하였다. 삼플루오르화 붕소의 에테르 착물이 가장 좋은 위치 선택성의 결과를 나타내는 것을 알았으며, 고리부가 생성물들의 구조를 여러가지 다양한 방법으로 규명하였다. Several 2-pyrones having conjugated diene unit were synthesized from glutaconic acid derivatives. Diels-Alder reaction between juglone and several substituted dienes was performed in various reaction conditions. Boron trifluoride etherate had the effect of improving regiospecific product to cycloaddition reaction. Structure of the reaction products were determined by spectroscopic methods.
두 가지 다른 음이온 작용기를 가진 아이오노머의 기계적인 성질
김희석,나연화,김준섭 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.1
The sulfonated poly(styrene-co-methacrylate) ionomer (7.6 mol% of ionic groups) was prepared by sulfonation of styrene-co-methacrylate (3.6 mol% of ions) polymer. The dynamic mechanical properties of this new ionomer, having two different ionic groups, were studied by using DMTA. We found that the new ionomer showed two glass transitions, the temperature ranges of which are similar to those of methacrylate ionomers containing ca. 8.7 mol% of ions. This result implies that the effect of the introduction of 4.0 mol% of sulfonate groups into the methacrylate ionomer on the mechanical properties is the same as that in a system of which we increase the methacrylate content by 4.0 mol%. From the findings, we conclude that the sulfonate and methacrylate ionic groups seem to form multiplets together: the multiplets are thought to be loosely bound because the carboxylates in the multiplets act as polar plasticizers. Thus the ion hopping of sulfonate groups occurs at the same temperature where the methacrylate ions start to hop.
스타이렌 아이오노머의 기계적인 성질에 미치는 혼합 양이온의 영향
김희석,나연화,이용혁,이법원,유지강,박기주,김준섭 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.1
The styrene-co-methacrylate ionomers neutralized with Na +, Ba2 +, and mixed cation of both were prepared. The dynamic mechanical properties of two cation-containing ionomers were measured and compared to those of the ionomers neutralized with only one type of cations. We found that in the ionomers with one type of cations the difference in the type of cation does not change the glass transition temperatures. It was found, however, that the cluster Tg of the mixed cation ionomer is lower than that of the single cation ionomers. Thus it was postulated that in the two-cation system the two cations in a solution have sufficient dynamics to form new type of multiplet containing both cations, which may be slightly bigger than that found in the single cation multiplet. The mechanical properties also imply that the strength of ion interactions in the multiplets of the two cation ionomer is thought to be weaker than that of the one cation ionomers. These two effects are believed to contribute the lower in the cluster glass transition of mixed cation system.
폴리스타이렌 동종블렌드의 형태-기계적 성질의 상관관계의 EHM모델에 의한 재해석
김준섭,박기주 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1
The mechanical properties of homoblends of sulfonated polystyrene with poly(styrene-co-4-vinylpyridine) were re-examined and re-interpreted by using EHM model of random ionomer. It was found that the homoblends show two glass transitions which are often seen in other random ionomers, and the amount of clustered materials of the homoblends is similar to that of random ionomers. However, the cluster Tg of the homoblend is lower than that of the random ionomer because of the weaker ionic interaction in the homoblend. It was also found that the EHM model can interpret well both these results and previous findings. In addition, no relationship between activation energies of the cluster Tg and strength of the ionic groups in multiplets was mentioned.
졸-겔법에 의해 합성한 실리카 졸의 GC 및 GC/MASS 분석
김선일,김준섭,유지강 조선대학교 생산기술연구소 1999 生産技術硏究 Vol.21 No.2
The optimal condition for reaction of silica sol at room temperature(25±1℃) was identified when the mole ratio of TEOS : EtOH : H₂0 : HCl was 0.345 : 0.390 : 0.612 : 1.21 x 10^(-3). The equilibrium state reached when the hydrolysis for TEOS was proceeded for 40~50 minutes at the room temperature, and the volume percent of ethanol which was detected from GC column reached to 61.6%. In order to identify the path for the molecular growth of intermediate, hydroxyl group of intermediate was change into TMS by the. TMCS, so that monomer and tetrasilicate were 92% based on the amount of TEOS by the GC/MASS.
폴리스타이렌 아이오노머와 액정중합체 블렌드의 기계적 성질
김희석,김준섭,최재곤,박기주,윤용국,진정일 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1
The dynamic mechanical properties of thermotropic liquid crystalline polyester (LCP) blends with polystyrene (PS) and Li sulfonated polystyrene (PSSLi) were investigated. It was found that PS forms an immiscible blend with LCP. However, above the matrix T_(g) of the PS, the addition of the LCP increases the modulus of the blend significantly because the LCP acts as filler below its T_(g). In PSSLi/LCP blend system, it was also found that, in the temperature range between two T_(g)s of the ionomer, the LCP acts as filler and thus increases the modulus of the blend. However, the filler effect of the LCP on the modulus decreases rapidly with increasing temperature and disappears above the T_(g) of the LCP. Finally, it was suggested that the PSSLi may be partially miscible with the LCP via ion-dipole interactions between a Li^(+) cation of the PSSLi and a carbonyl group of the LCP.
Acoustic Duct 내부에 장착된 아이오노머의 이온기 변화에 따른 흡음패턴 측정
장순석,김준섭,이제형,박재철 조선대학교 전자정보통신연구소 2001 電子情報通信硏究所論文誌 Vol.4 No.2
Nowadays, as the industrial technology and instrumentation are developed, the interest of the characteristic improvement of sound absorbing materials is rising. Recently new sound absorbing materials are being developed and manufactured for commercialization. But most of sound absorbing materials are polymer-typed or are fabricated by polymers (mixtures of polymer and glass fiber, asbestos...) for better physical characteristic. However, there was not much research about sound absorption change by the change of the ionic nature. In this paper, I composed polymers that include alkaline or acid, or other polymer that have the ionic nature to improve sound absorption characteristic and searched the characteristic pattern of the sound absorption of polymer. I used probe microphone instead of 1/4 condenser microphone such as two- microphone method in order to measure in-duct absorption coefficient of specimen of ionomers that are thin and small so that measuring absorption coefficient is not well defined.