• Composites Research
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• 제31권4호
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• pp.122-127
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• 2018

섬유강화고분자복합재료(CFRP, Carbon Fiber Reinforced Plastics)의 경량화는 자동차 및 항공 분야에서 끊임없이 요구되고 있으며, 구조용 폼과 CFRP를 혼합하여 샌드위치 복합재료로 사용되고 있다. 본 연구에서는 열경화성 소재인 에폭시 폼과 폴리우레탄 폼 및 열가소성 소재인 PET 폼과 PVC 폼의 조성 차이에 따른 폼의 형상 및 열 노화를 통해 변화되는 기계적 특성 변화를 관찰하였다. 성형한 에폭시 폼, 폴리우레탄 폼 및 상용화된 PET 폼과 PVC폼을 180도에서 열 노화시켰으며, 30, 60, 120, 180분의 노화시간에 따라 구조용 폼의 변화를 광학 현미경 및 만능시험기로 폼 셀의 형상 및 압축강도를 평가하였다. 궁극적으로 에폭시 폼이 가장 높은 2.6 MPa의 압축강도를 가졌으며, 열 노화 조건에서도 물성저하나 형상의 변화가 거의 발생되지 않았다. 이는 에폭시 폼이 타 구조용 폼에 비해 열 노화 조건에서 후경화되어 강직한 조성을 이루며, 타 구조용 폼과는 다르게 내열 특성이 우수하기 때문에 고온용 구조용 폼으로 적용하기 적합한 소재임을 확인하였다.

• 한국고분자학회지:고분자과학과기술
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• 제3권5호
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• pp.406-411
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• 1992

• 한국고분자학회지:고분자과학과기술
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• 제6권3호
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• pp.226-241
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• 1995

• 한국고분자학회지:고분자과학과기술
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• 제4권5호
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• pp.339-351
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• 1993

• Carbon letters
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• 제22권
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• pp.105-109
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• 2017

• 한국응용과학기술학회지
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• 제30권3호
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• pp.472-479
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• 2013

The conductive polymer composites recently became increasingly to many fields of industry due to their electrical properties. To understand these properties of composites, electrical properties were measured and were studied relatively. Electrical conductivity measurements showed percolation phenomena. Percolation theories are frequently applied to describe the insulator-to-conductor transitions in composites made of a conductive filler and an insulating matrix. It has been showed both experimentally and theoretically that the percolation threshold strongly depends on the aspect ratio of filler particles. The critical concentration of percolation formed is defined as the percolation threshold. This paper was to study epoxy resin filled with copper. The experiment was made with vehicle such as epoxy resin replenished with copper powder and the study about their practical use was performed in order to apply to electric and electronic industry as well as general field. The volume specific resistance of epoxy resin composites was 3.065~13.325 in using copper powder. The weight loss of conductive composites happened from $350^{\circ}C{\sim}470^{\circ}C$.

• 한국도로학회논문집
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• 제14권4호
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• pp.51-61
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• 2012

PURPOSES : This study deals with the working life of polymer concrete, which is typically used as a repair or overlay material for portland cement concrete pavements. METHODS : In the scope of this study, laboratory testing was conducted on fresh MMA modified UP polymer concrete, which uses an MMA monomer for viscosity adjustment and strength improvement of UP resin. The experimental variables were temperature (-20 to $+20^{\circ}C$) and binder components (MMA, MEKPO, and DMA). RESULTS : The result showed that the optimum binder ratios for polymer concrete production were 12, 11, and 10 wt.% when the MMA contents were 20, 30, and 40 wt.%, respectively. The working life of polymer concrete depending on temperature and binder components could be expressed by a logarithmic functional formula. The coefficient of variation for each binder component was the highest for DMA content while the lowest for MEKPO content. Also, the contents of each binder component for ensuring the working life of 60 minutes were proposed. CONCLUSIONS : Ultimately, the present study derived a linear regression equation estimating 60 minutes working life based on the setting times of each binder component.

• 폴리머
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• 제35권2호
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• pp.141-145
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• 2011

In-mold decoration 포일의 경질 코팅 층에 사용하는 수지를 대상으로 전자빔(electron beam, EB) 경화에 관한 연구를 수행하였다. 시료에 다른 양의 EB를 조사하고 경화 반응 정도를 Fourier transform infrared(FTIR) spectroscopy를 사용하여 관찰하였다. EB 조사선량 증가에 따른 코팅 물성의 변화를 표면 경도와 내마모성을 중심으로 알아보았다. 또한 나노 입자 첨가가 코팅 물성에 미치는 영향을 조사하였다. 본 연구로부터 얻은 실험적 결과는 자외선(ultraviolet, UV) 경화 시스템과 유사한 EB 경화 시스템의 상업적 개발에 이용될 수 있을 것으로 기대된다.

• Elastomers and Composites
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• 제51권4호
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• pp.275-279
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• 2016

Additive manufacturing or 3D printing is a new manufacturing process and its application is getting growth. However, the product qualities such as mechanical strength, dimensional accuracy, and surface quality are low compared with conventional manufacturing process such as molding and machining. In this study not only mechanical characteristics of polymer sandwich panel having three dimensional core layer but also mechanical characteristics of core layer itself were analyzed. The shape of three dimensional core layer was pyramidal kagome structure. This core layer was fabricated by two different methods, injection molding with PP resin and material jetting type 3D printing with acrylic photo curable resin. The material for face sheets in the polymer sandwich panel was PP. Maximum load, stiffness, and elongation at break were examined for core layers fabricated by two different methods and also assembled polymer sandwich panels. 3D printed core showed brittle behavior, but the brittleness decreased in polymer sandwich panel containing 3D printed core. The availability of 3D printed article for the three dimensional core layer of polymer sandwich panel was verified.

• 한국건축시공학회지
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• 제8권6호
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• pp.131-137
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• 2008

In recent years, the light-weight aggregate has widely been used to reduce the weight of construction structures, and to achieve the thermal insulation of building structures. The purpose of this study is to evaluate the heat resistance of polymer concrete composites with light-weight aggregate made by binders as resin and cement with polymer dispersion. The light-weight polymer concrete composites are prepared with various conditions such as binder content, filler content, void-filling ratio, light-weight aggregate content and polymer-cement ratio, and tested for heat resistant test, and measured the weight reducing ratio, strengths and exhaustion content of gas such as CO, NO and $SO_2$. From the test results, the weight reducing ratio of light weight polymer concrete using UP binder after heat resistance test increase with an increase in the UP content irrespective of the filler content. The weight reducing ratio of polymer cement concrete is considerably smaller than that of UP concrete. In general, the strengths after heat resistance of polymer concrete composites are reduced about 40 to 65% compared with those before test. The exhausted quantity of CO, NO and $SO_2$ gases in polymer concrete composites is less than EPS(Expanded poly styrene). From the this study, it is confirmed that the many types gases discharge according to binder type of polymer concrete composites, its amount is controlled by selection of the binder type and mix proportions.