• Fibers and Polymers
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• v.7 no.4
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• pp.328-332
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• 2006

Poly(ethylene terephthalate) (PET) and poly(ethylene glycol) (PEG) copolymers cross-linked with pentaerythritol, a four-way cross-linker, are prepared to compare their mechanical and shape memory properties with the one cross-linked by glycerol. Composition of PEG and pentaerythritol is varied to search for the one with the best mechanical and shape memory properties. The highest shape recovery rate is observed for the copolymer composed of 30 mol% PEG-200 and 2.5 mol% pentaerythritol. Four-way cross-linking by pentaerythritol significantly improves shape recovery rate and retention of high shape recovery rate after repeated use compared to the one cross-linked by glycerol, a three-way cross-linker, and difference and advantage of additional cross-linking point are discussed.

• Proceedings of the Korean Society of Rheology Conference
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• 2000.11a
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• pp.7-10
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• 2000

• Polymer Science and Technology
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• v.23 no.2
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• pp.154-163
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• 2012

• Polymer Science and Technology
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• v.19 no.3
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• pp.233-240
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• 2008

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.502-504
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• 2009

We demonstrate a pixel-isolated bistable twist-splay namatic (PI-BTSN) liquid crystal (LC) cell which has two stable states of splay and ${\pi}$-twist. Each state is stabilized by a multi-dimensional anchoring effect of pixel-isolating polymer walls without any chiral additives. Polymer walls are formed around the pixel region by anisotropic phase separation between LCs and reactive mesogens. Switching between the two states is archived by using vertical and horizontal electric fields. The memory mode of the fabricated LC cell has shown infinity memory time.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.195.2-195.2
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• 2013

플라즈마 중합 증착기술을 이용하여 ppMMA (plasma polymerized methyl methacrylate) 및 ppS (plasma polymerized styrene) 박막을 제작하고, ppMMA를 게이트 절연층, polymer electret인 ppS를 메모리층으로 한 전계효과트랜지스터 기반 유기 메모리 소자를 제작하였다. 메모리층인 ppS의 두께를 각각 30, 60, 90 nm로 달리한 유기 메모리 소자가 C-V 및 I-V 특성에서 나타내는 히스테리시스 현상을 분석하여 메모리 특성을 평가했으며, 메모리층의 두께 변화에 따른 유기 메모리 소자의 성능을 비교분석하였다.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.303-304
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• 2003

Conducting polymers show several unique features, wherein electrical and optical properties change drastically during electrochemical reaction. By making use of these phenomena, several electronic devices have been fabricated, for instance, electrochromic displays, rechargeable batteries and electroplasticity memory devices. Electromechanical actuators using conducting polymers have been proposed by Baughman et. al [1]. (omitted)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.789-790
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• 2011

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.340-345
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• 2016

Railway vehicle battery is supplying the power required for the initial start-up of the train, in the event of a fault in the vehicle, or catenary for supplying emergency power is one of the components are very important. Currently, the railway vehicles such as nickel-cadmium batteries are being used [1,2]. Ni-Cd batteries as a battery installed in the railway vehicles have a strong corrosion resistance is included, The charge-discharge performance is significantly degraded in cold weather, there is a danger of deterioration or explosion. Train accidents have been caused a lot of damage due to rapid deterioration and cracking of the battery and memory due to the effect of Ni-Cd batteries. In order to solve the problems, There is no risk of degradation, deterioration and leakage, cracking and exploding. maintenance is simple and applied measures proposed to apply Lithium Polymer battery of high performance. In addition, the lack of capacity problems identified by testing the different special systems is replaced by a 70Ah lithium-polymer battery is possible without changing the batteries of 50Ah caused by installing additional equipment in existing older trains were applied to the vehicle.

• Macromolecular Research
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• v.16 no.7
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• pp.644-650
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• 2008

This study examined the effect of nanoclays on the shape memory behavior of polyurethane (PU) in fibrous form. A cation was introduced into the PU molecules to disperse the organo-nanoclay (MMT) into poly($\varepsilon$-caprolactone) (PCL)-based PU (PCL-PU). The MMT/PCL-PU nanocomposites were then spun into fibers through melt-processing. The shape memory performance of the spun fibers was examined using a variety of thermo-mechanical tests including a new method to determine the transition temperature of shape memory polymers. The MMTs showed an improved the fixity strain rate of the MMT /PCL- PU fibers but a slight decrease in their recovery strain rate. This was explained by the limited movement of PU molecules due to the presence of nanoclays. The shape memory performance of the MMT/PCL-PU fibers was not enhanced significantly by the nanoclays. However, their recovery power was improved significantly up to a strain of approximately 50%.