• Safety and Health at Work
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• 제13권1호
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• pp.126-128
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• 2022

• Safety and Health at Work
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• 제13권1호
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• pp.129-130
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• 2022

• Journal of Pharmaceutical Investigation
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• 제24권4호
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• pp.251-256
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• 1994

Polypropylene glycol (M.W. 4000) was crosslinked and chain-extended by using triisocyanate and diisocyanate to synthesize rubbery and water swellable hydrogels. Model drugs, i.e., sodium salicylate and indomethacin were incorporated in the polymer matrices by swelling loading. The drug release rates of drugs could be regulated by varying the degrees of crosslinking and chain-extension. Whereas, no correlation was observed between the drug release profiles and the swelling behaviours of the matrices. The release of drugs from the matrices was considered to be governed by the mobility and mesh size of the polymer chains in the matrices.

• 폴리머
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• 제25권3호
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• pp.343-348
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• 2001

Perfluorinated polyether diol(Fomblin ZDOL$ZDOL^{(R)}$)과 4,4'-diphenyl methane diisocyanate(MDI)로부터 합성된 불소화된 폴리우레탄 탄성체의 기계적 성질과 혈소판 점착 특성을 연구하였다. Fomblin 함량과 혼합 사용된 polyether polyol의 종류에 따른 기계적 성질의 검토를 인장실험 및 dynamic mechanical analysis를 통해 행하였다. 또한 혈소판 점착실험을 통해 불소화된 폴리우레탄 탄성체의 혈액적합성을 평가하였다. 기계적 물성은 혼합된 polyether polyol의 종류와 함량에 영향을 받았고, 혈소판 점착은 모든 불소화된 폴리우레탄에서 불소화 함량의 증가에 따라 감소하였다.

• 대한화학회지
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• 제25권4호
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• pp.214-218
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• 1981

Solid인 Hexogen 존재하에서 hydroxyl-terminated polybutadiene과 isophorone diisocyanate의 혼성중합반응속도에 관하여 연구하였다. 중합반응속도는 Hexogen의 첨가량이 증가할 수록 빠르게 나타났지만, Hexogen의 촉매적 역할은 없었으며, 오직 entropy control에 의한 반응임을 밝혔다. 이 반응은 2차 반응속도법칙에 잘 일치하며, activation energy는 8.4 Kcal/mole로 거의 일정하다.

• 대한화학회지
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• 제25권3호
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• pp.140-144
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• 1981

추진제 성형에 쓰이는 isophorone diisocyanate의 구조와 반응성을 EHT, DNDO/2 및 STO-3G 방법으로 고찰하였다. 반응성은 -NCO기의 탄소원자의 양전하로 결정되며, 이 화합물의 구조는 반응성이 느리고 균일한 matrix 성형이 이루어지도록 되어 있는 것을 알았다.

• 한국염색가공학회지
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• 제10권2호
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• pp.37-44
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• 1998

In this study, the polyurethane microcapsules containing disperse dye were prepared by in-situ polymerization method using hexamethylene diisocyanate (HDI, aliphatic type) and m-xylene diisocyanate(XDI, aromatic type) with ethylene glycol (EG) And the size, shape, particle size distribution, and breaking behavior of microcapsules prepared were investigated. The size and shape of microcapsule were observed by scanning electron microscope (SEM) . The particle size distribution was analyzed by image analyzer. The breaking behavior of microcapsule was checked by measuring the optical density of solution that the disperse dye was dissolved after the microcapsule was broken by constant pressure. The particle size was inversely proportional to the stirring speed, and the size of microcapsule prepared from HDI and EG was smaller than that of microcapsule prepared from XDI and EG. Aliphatic type microcapsule was broken easily, compared with aromatic type one. It was considered due to the difference of reactivity between HDI and XDI. And the microcapsule prepared by stirring strongly was broken easily.

• 한국가스학회:학술대회논문집
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• 한국가스학회 1999년도 추계학술발표회 논문집
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• pp.81-90
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• 1999

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 추계총회 및 학술발표회 논문집
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• pp.126-130
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• 1997

A series of Thermoplastic polyurethane elastomers was prepared via a two-step polymerization process. The NCO/OH feed ratio of polyurethane synthesized in this study was varied from 1 to 1.3. Studies have been made on the effects of chemical and physical cross-linkina, and the properties of thermoplastic polyurethane elastomers based on isophorone diisocyanate (IPDI)/1,4-butanediol (BD)/poly(propylene glycol) (PPG, MW:2000), isophorone diisocyanate (IPDI)/BD /poly(oxytetramethylene) glycol (PTMG, MW:2000) was compared. These materials were characterized using FTIR spectrometer, dynamic mechanical thermal analyzer, and tensile retraction tester. PTMG based polyurethane elastomers showed higher elasomeric behavior than PPG based polyurethane elastomers at the same NCO/OH ratio. This feature has been connected with the specific nature of the polyols. The permanent set(%) was decreased with increasing maximum elongation from 50% to 300%.

• 반도체디스플레이기술학회지
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• 제17권2호
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• pp.47-52
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• 2018

The three polyols, poly(trimethylene ether) glycol 2000, poly(tetramethylene ether) glycol 2000 and poly (tetramethylene ether) glycol 1000 were reacted with 4,4-diphenylmethane diisocyanate to get polyurethanes. The synthesized three polyurethanes were measured by FT-IR, NMR for investigating chemical structures. Through two spectroscophical methods, It is found that urethane group exists in the three polymers. From the evaluation of hardness, glass transition temperature, tensile strength, and water resistance, the results showed increasing order of Poly(tetramethylene ether) glycol 1000 > Poly(trimethylene ether) glycol 2000 > Poly(tetramethylene ether) glycol 2000 with the content of hard segment in polyurethane.