• Polymer(Korea)
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• v.31 no.6
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• pp.485-490
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• 2007

Hard coating was made on a polycarbonate plate using a sol-gel process with a melamine derivative and silicates, and examined as potential substitutes for automobile glass. Methylated poly(melamine-co-formaldehyde), tetraethoxysilane, and phenyltriethoxysilane were used to form a coating solution. The coatings on the polycarbonate plate were deposited using a sol-gel process. Poly(methyl methacrylate) was coated on the surface of polycarbonate in order to improve adhesion property. The optimum conditions and formulation to obtain excellent physical properties of the coating were determined. Adding the melamine derivative to the coating solution, the pencil hardness of the coating was improved. The hardness of a 3H class pencil, excellent abrasion resistance, and surface uniformity were found in the coated polycarbonate surface.

• Polymer Science and Technology
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• v.4 no.6
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• pp.439-443
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• 1993

• The Korean Journal of Rheology
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• v.8 no.2
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• pp.119-128
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• 1996

폴리프로필렌(PP)/폴리카보네이트(PC) 블렌드의 유변학적 고찰을 통해 블렌드의 수 축현상과 분상상의 변형의 연관성을 연구했다. 블렌드의 수축현상은 압축과정에서 변형됐던 분산상이 고온에서 다시 원래의 무변형 상태로 복귀하면서 나타나는 탄성변형의 풀림으로 추정되고 압출팽윤의 데이터와도 부합된다. 압출온도를 최대한 낮게 해서(25$0^{\circ}C$) 제조한 블 렌드의 경우가 최대한 높게 한 경우 (29$0^{\circ}C$)보다 수축이더 큰 사실을 설명하기 위하여 순수 PC와 PP의 전단점도비와 신장점도비를 측정 비교한 결과 두 값이 공히 높은 온도의 경우 가 오히려 작게 되어 점성에 의한 분산상의 전단변형이나 신장변형이 수축의 원인이 아니라 는 것을 알아다. 한편 법선응력과 전단응력의 데이터로부터 얻은 물질풀림시간의 비는 낮은 온도의 경우가 작아서 수축현상이 분산상의 탄성에 의한 변형이라는 것을 확인했다.

• Polymer(Korea)
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• v.24 no.5
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• pp.682-689
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• 2000

The information related to the interaction energy between repeat units is essential for the production of useful polymer blends via molecular structure design. Based on the interaction energies obtained here, a method for the fabrication of miscible blend was suggested. An investigation related to the equilibrium phase behavior of polymer blends of various polycarbonates with various polymethacrylates was performed and then based on the obtained interaction information miscible polymer blends were produced by controling molecular structure of polymer. Binary interaction energies between repeat units were calculated from the lower critical solution temperature-type phase boundary using an equation of state combined with binary interaction model.

• Clean Technology
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• v.24 no.3
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• pp.190-197
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• 2018

Various waterborne polyurethanes (WPU) with three different types of polyol such as ester type polyol [adipic acid (A)/BD/3-methyl-1,5-pentandiol (MPD) and A/BD]//carbonate type polyol (C/HD/MPD, C/HD, C/BD)//ether type polyol (PTMG) were prepared in this study. This study focused on the effect of polyol type on the properties of WPU. Soft segment Tg (Tgs), 100% elastic modulus and tensile strength were highest when using carbonate polyol, followed by ester polyol and ether polyol, while those of elongation showed the opposite trend. The WPU synthesized with MPD - containing polyol showed lower Tgs, 100% elasticity and strength, and higher elongation than MPD - free WPU. The % transmittance and transparency of the WPU film containing the MPD component was superior to that of the WPU film containing no MPD component, and it was found that the film based on carbonate polyol was slightly better than the film based on ester polyol and ether polyol.

• Clean Technology
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• v.17 no.3
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• pp.244-249
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• 2011

We synthesized low molecular-weight polymers bearing hydrophobic and hydrophilic parts in a chain through $CO_2$/propylene oxide copolymerization. When hydrophilic poly (ethylene glycol) bearing -OH group (s) at the end group (s) was added as a chain transfer agent in the $CO_2$/propylene oxide copolymerization catalyzed by a highly active catalyst, block polymers were formed. If poly (ethylene glycol) (PEG) bearing -OH group only at an end was fed, PEG-block-PPC diblock copolymer was obtained. When PEG bearing -OH group at both ends was fed, PPC-block-PEG-block-PPC triblock copolymer was obtained. We confirmed formation of block copolymers by $^1H$-NMR spectroscopy and GPC studies.

• Journal of the Korean Society for Advanced Composite Structures
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• v.5 no.3
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• pp.32-36
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• 2014

This study analyzes performance-weight ratio of polycarbonate(PC) pigpen and steel pigpen. The finite element models using the ANSYS program described in this paper is attractive not only because it shows excellent accuracy in analysis but also it shows the benefit of parameter study by using APDL. We have performed a parameter study by the width variation of PC pigpen. And we compared and analyzed the results of PC pigpen and steel pigpen. From the numerical examples, we confirmed the validity of PC pigpen.

• Journal of the Korean Society for Advanced Composite Structures
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• v.5 no.4
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• pp.58-64
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• 2014

This study analyzes performance-cost ratio of various polycarbonate(PC) pigpen. The finite element models using the ANSYS program described in this paper is attractive not only because it shows excellent accuracy in analysis but also it shows the benefit of parameter study by using APDL. We have performed various parameter study of total 6 models. And we compared and analyzed the results of 6 models. From the numerical examples, we recommend model M2. Model M2 is PC pigpen with steel in PC.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.78-85
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• 2010

Creep characteristic is an important failure mechanism when evaluating engineering materials that are soft material as polymers or used as mechanical elements at high temperatures. One of the popular thermo-elastic polymers, Polycarbonate(PC) which is used broadly for engineering polymer, as it has excellent mechanical and thermal properties compared to other polymers, was studied for creep characteristic at various level of stresses and temperatures. From the experimental results, the creep limit of PC at room temperature is 85 % of tensile strength. which is higher than PE (75%)at room temperature. Also the creep limits decreased exponentially as the temperatures increased, up to 50 % of the melting point($267^{\circ}C$). Also the first and third stage among the three creep stages was non-existent nor was there any rupture failure which occurred for many metals.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.51-54
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• 2007

타겟 전압 제어를 통한 반응성 스퍼터링 방법과 유도결합 플라즈마(ICP: inductively coupled plasma)를 통해 산화알루미늄 박막을 증착하였다. 폴리카보네이트 기판과 산화알루미늄 박막사이의 접착력은 플라즈마 표면처리 하여 향상시켰다. 박막 특성은 ICP power 변화에 대한 경도, 구조, 밀도변화, 투과율, 증착속도, 표면 거칠기 및 잔류응력을 조사하여 보호코팅으로서 성능을 평가하였다.