• 한국응용과학기술학회지
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• 제20권4호
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• pp.353-357
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• 2003

Sodium azide (SA) is commonly used as propellant for inflating automatic safety bags and other chemical manufacturing purposes. The investigation of potentially thermal hazard of sodium azide and its mixture with polymers are very important because it can occur an expected traffic accident so we took a experiment s using different scanning calorimeter (DSC) in nitrogen atmosphere. The decomposition temperature were about $350{\sim}450^{\circ}C$. We could find not only exothermic reaction was remarkably decreased in mixture s of acrylonitrile-butadiene-styrene (ABS) and polyvinyl chloride (PVC), but also increasing mixed rate of ABS, polyvinyl alcohol (PVA) and polymethyl methacrylate (PMMA) decreased thermal decomposition heat.

• 한국재료학회지
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• 제16권4호
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• pp.272-275
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• 2006

In order to evaluate the possibility of Polymethyl methacrylate (PMMA) as a binder on hydroxyapatite (HAp) which has good biocompatibility, the properties of HAp compacts with PMMA were examined. When adding 50 wt% of PMMA on HAp and pressed, the compression strength and the hardness of the compacting body were 168MPa and 55 Hv, respectively, and the strength of compacts was higher than that of cortical bone and the hardness was similar to the value of molar. We demonstrated that HAp ceramics can be obtained without additional heat treatment and machining of the ceramic was feasible. Therefore, the HAp compacts have potential to apply to implant or artificial bone after the clinical trials guarantees biocompatibility of it.

• Clinics in Shoulder and Elbow
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• 제23권3호
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• pp.156-158
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• 2020

PHILOS plate fixation in osteoporotic proximal humerus fracture of old age is well-known for high complication rate, especially metal failure, providing various augmentation techniques, such as calcium phosphate cement, allogenous or autologous bone graft. We report a case of polymethyl methacrylate augmentation to provide appropriate reduction with a significant mechanical support. This can be a treatment option for displaced unstable osteoporotic proximal humerus fracture with marked bony defect.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
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• pp.45-48
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• 2007

기존에 사용되는 피에조 타입의 센서는 추력의 측정 범위가 제한되어 있으므로 이를 개선하고자 레이져 변위측정기와 cantilever를 이용하여 변위 측정 장치를 개선하였고, 스테인레스 캐필러리를 이용하여 추력 모델을 만든 후 추력을 측정하였다. 이와 더불어 extrude shape의 노즐을 갖는 마이크로 추력 장치를 PMMA(Polymethyl methacrylate)를 이용하여 공정하였으며, 매니스커스의 형상 변화를 관찰하였다.

• 한국기계가공학회지
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• 제17권5호
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• pp.111-116
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• 2018

Thermal fusion bonding is a method to enclose open microchannels fabricated on polymer chips for use in lab-on-a-chip (LOC) devices. Polymethyl methacrylate (PMMA) is utilized in various biomedical-microelectromechanical systems (bio-MEMS) applications, such as medical diagnostic kits, biosensors, and drug delivery systems. These applications utilize PMMAs biochemical compatibility, optical transparency, and mold characteristics. In this paper, we elucidate both the conformational entanglement of PMMA molecules at the contact interfacial regime, and the qualitative nature of the thermal fusion bonding phenomena through systematic molecular dynamics simulations.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제37회 하계학술대회 초록집
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• pp.260-260
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• 2009

• Elastomers and Composites
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• 제22권4호
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• pp.324-332
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• 1987

PMMA와 TBBA의 혼합비를 변화시킨 시료를 질소기류 하에서 비등온 열중량 분석법으로 가열속도 $1-20^{\circ}C/min$, 등온분해온도 $200-300^{\circ}C$로 열분해시킨 시료를 적외선 분광분석한 결과 TBBA의 함량 증가에 따라 활성화에너지 값은 Friedman법으로 28-46 Kcal/mol, Ozawa법으로 28-38 Kcal/mol로 증가 하였다. PMMA에 TBBA의 첨가에 따른 열분해반응은 주쇄 분해반응으로 이루어지며 실제 열중량곡선과 거의 일치되는 최적의 분해반응 모델식을 산출할 수 있었다.

• 전기학회논문지
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• 제56권2호
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• pp.334-337
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• 2007

After the advent of micro-Total Analysis Systems(${\mu}-TAS$) based on silicon various polymer for microfluidic chip has been studied. Polymer materials for microfluidic compared with silicon and glass which were traditional materials of a microfluidic chip, have the advantages of economical efficiency simple manufacturing process and wide materials selectivity corresponding to fluids. Surface energy of polymers we, however lower than silicon or glass. To overcome this problem, various surface modification methods have been investigated. The surface modification using laser has the advantage of the simple experiment that only directly irradiated laser beam on the material surface in the air. This work discuss the surface modification of polymethly methacrylate(PMMA) by 4th harmonic Nd:YAG laser (${\lambda}266nm$, pulse) treatment. After the laser treatment, the PMMA surface was investigated using a contact angle measuring instrument. The contact angle was decreased with a increase of the surface oxygen content. This result means the surface energy of PMMA was increased by the laser treatment without changing of its bulk characteristics.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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• pp.29-32
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• 2005

Poly (methyl methacrylate) (PMMA) is one of the promising representive of polymer gate dielectric for its high resistivity and sutible dielectric constant. PMMA (Mw=96700) films were prepared on p-Si by spin coating method. PMMA were coated compactively and flatly as observeed by AFM. MIS(Al/PMMA/p-Si) structure was made and capacitance-voltage (C-V) and current-voltage (I-V) measurements were done with PMMA films for different thermal treatment temperature. PMMA films were showed proper dielectric constant and breakdown voltage. Above the glass transition temperature PMMA films degraded. C-V measured at various frequencies, dielectric constant increased a little. The absence of hysteresis in the C-V characteristics, which eliminate the possibility of mobile charges in the PMMA films. The observed thermal stability, smooth surfaces, dielectric constant, I-V behavior implies PMMA formed by spin coating can be used as an efficient gate dielectric layer in OTFTs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1924-1926
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• 2005

Poly(methyl methacrylate) (PMMA) is one of the promising representive of polymer gate dielectric for its high resistivity and sutible dielectric constant. PMMA (Mw=96700) films were prepared on p-Si by spin coating method. PMMA were coated compactively and flatly as observes by AFM. MIS(Al/PMMA/p-Si) structure was made and capacitance-voltage (C-V) and current-voltage (I-V) measurements were done with PMMA films for repeated annealing cycles at $100^{\circ}C$. 1-V measured at various delay times $(0{\sim}20sec)$ showed little change and the absence of hysteresis in the I-V characteristics with delay times, which eliminate the possibility of deep traps in the PMMA films. The observed thermal stability, smooth surfaces, dielectric constant, I-V behavior implies PMMA formed by spin coating can be used as an efficient gate dielectric layer in OTFTs.