• Carbon letters
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• 제19권
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• pp.47-56
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• 2016

In this study, the fracture behavior of a thermoplastic-modified epoxy resin reinforced with continuous carbon fibers for two levels of fiber-matrix adhesion was performed. A carbon fiber with commercial sizing was used and also treated with a known silane, (3-glycidoxy propyl trimethoxysilane) coupling agent. Toughness was determined using the double cantilever test, together with surface analysis after failure using scanning electron microscope. The presence of polysulfone particles improved the fracture behavior of the composite, but fiber-matrix adhesion seemed to play a very important role in the performance of the composite material. There appeared to be a synergy between the matrix modifier and the fiber-matrix adhesion coupling agent.

• 접착 및 계면
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• 제3권4호
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• pp.44-52
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• 2002

Composite materials are created by combining two or more component to achieve desired properties which could not be obtained with the separate components. The use of reinforcing fillers, which can reduce material costs and improve certain properties, is increasing in thermoplastic polymer composites. Currently, various inorganic fillers such as talc, mica, clay, glass fiber and calcium carbonate are being incorporated into thermoplastic composites. Nevertheless, lignocellulose fibers have drawn attention due to their abundant availability, low cost and renewable nature. In recent, interest has grown in composites made from lignocellulose fiber in thermoplastic polymer matrices, particularly for low cost/high volume applications. In addition to high specific properties, lignocellulose fibers offer a number of benefits for lignocellulose fiber/thermoplastic polymer composites. These include low hardness, which minimize abrasion of the equipment during processing, relatively low density, biodegradability, and low cost on a unit-volume basis. In spite of the advantage mentioned above, the use of lignocellulose fibers in thermoplastic polymer composites has been plagued by difficulties in obtaining good dispersion and strong interfacial adhesion because lignocellulose fiber is hydrophilic and thermoplastic polymer is hydrophobic. The application of lignocellulose fibers as reinforcements in composite materials requires, just as for glass-fiber reinforced composites, a strong adhesion between the fiber and the matrix regardless of whether a traditional polymer matrix, a biodegradable polymer matrix or cement is used. Further this article gives a survey about physical and chemical treatment methods which improve the fiber matrix adhesion, their results and effects on the physical properties of composites. Coupling agents in lignocellulose fiber and polymer composites play a very important role in improving the compatibility and adhesion between polar lignocellulose fiber and non-polar polymeric matrices. In this article, we also review various kinds of coupling agent and interfacial mechanism or phenomena between lignocellulose fiber and thermoplastic polymer.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 1999년도 추계학술발표대회 논문집
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• pp.40-43
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• 1999

Electrochemical surface treatment of PAN-based carbon fibers in acidic electrolyte has been studied in increasing the surface functional groups on fiber surfaces for the improvement of fiber-matrix adhesion of the resulting composites. According to the FT-IR and XPS measurements, it reveals that the oxygen functional groups on fibers are largely influence on the composite mechanical behaviors, whereas the nitrogen functional groups are not affected in the system. In this work, a good correlation between surface functionality and mechanical properties is established.

• Composites Research
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• 제25권6호
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• pp.205-210
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• 2012

전기저항 측정법을 이용하여 단일 탄소섬유의 인장 실험을 실시하였다. 탄소섬유의 전도성을 이용하여 인장하중에 따른 신율과 전기저항 변화도간의 관계를 연구하였다. 섬유 인장 과정동안에 일정 신율 거리상 응력과 전기저항 변화율간의 상관관계를 통계적으로 정리하였다. 결과에 대해 추세선을 그어 섬유의 변형에 따른 거동 모델을 구성하였다. 프레그먼테이션 시편을 이용하여 인장 실험에 따른 인장 응력이 재료 내부로 전달되면서, 시편 내부 탄소섬유에도 인장 응력이 가해져 기지보다 섬유가 먼저 파괴되었다. 이 경우 탄소섬유의 전기저항 변화도를 측정한 결과 값을 탄소섬유의 거동 모델에 대입하여 프레그먼테이션 시편 내부에 있었던 탄소섬유의 거동을 분석할 수 있었다. 탄소섬유의 인장 신율을 예측하고 프레그먼테이션 시편의 실제 신율을 비교하여 섬유와 기지 사이에 발생된 섬유 미끌림 정도를 확인하였다. 섬유 미끌림 정도의 수치가 클 경우, 기지와 섬유 간 계면 상태가 약한 접합의 상태였다. 이러한 결과를 확인하기 위해서 접착일 평가법을 이용하였으며, 두 실험법의 결과, 동일한 경향임을 확인하였다.

• Elastomers and Composites
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• 제54권3호
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• pp.182-187
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• 2019

To improve the mechanical properties of glass-fiber-reinforced polypropylene (PP) composites through interfacial adhesion control between the PP matrix and glass fiber, the surface of the glass fiber was modified with PP-graft-maleic anhydride (MAPP). Surface modification of the glass fiber was carried out through the well-known hydrolysis-condensation reaction using 3-aminopropyltriethoxy silane, and then subsequently treated with MAPP to produce the desired MAPP-anchored glass fiber (MAPP-a-GF). The glass-fiber-reinforced PP composites were prepared by typical melt-mixing technique. The effect of chemical modification of the glass fiber surface on the mechanical properties of composites was investigated. The resulting mechanical and morphological properties showed improved interfacial adhesion between the MAPP-a-GF and PP matrix in the composites.

• 한국염색가공학회지
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• 제27권1호
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• pp.18-26
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• 2015

para-aramid fibers were treated by atmosphere air plasma to improve the interfacial adhesion. The wettability of plasma-treated aramid fiber was observed by means of dynamic contact angle surface free energy measurement. Surface roughness were investigated with the help of scanning electron microscopy and atomic force microscopy. The tensile test of aramid fiber roving was carried out to determine the effect of plasma surface treatments on the mechanical properties of the fibers. A pull-out force test was carried out to observe the interfacial adhesion effect with matrix material. It was found that surface modification and a chemical component ratio of the aramid fibers improved wettability and adhesion characterization. After oxygen plasma, it was indicated that modified the surface roughness of aramid fiber increased mechanical interlocking between the fiber surface and vinylester resin. Consequently the oxygen plasma treatment is able to improve fiber-matrix adhesion through excited functional group and etching effect on fiber surface.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.401-404
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• 2006

Much of requirements to the civil and building structures have been changed in accordance with the social and economic progress. Ductility of high performance fiber reinforced cementitious composites(HPFRCCs), which exhibit strain hardening and multiple crackling characteristics under the uniaxial tensile stress is drastically improved. In HPFRCC application, PVA fiber has been dominantly used as a reinforcement because of its excellent alkali resistant nature as well as high strength. But the inherent strong hydrophilicity of PVA fiber promotes the moisture absorption in cement matrix and thus it may cause the corrosion of steel structure. Therefore, it is necessary to control the interfacial adhesion of cement composites. In present study, to control the interfacial adhesion of the cementitious composites reinforced by PVA fiber, UV irradiation of the PVA fiber were performed and their effects on the adhesion property and general characteristics were investigated extensively.

• Journal of the Optical Society of Korea
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• 제18권3호
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• pp.251-255
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• 2014

A fiber diffuser sheet based on poly (ethylene naphthalate) (PEN) and poly (methylpentene) (PMP) has shown potential for liquid crystal display backlight units, but these materials have an interfacial adhesion problem. To improve the interfacial adhesion between the fibers and matrix components, we have proposed the use of amorphous poly (cyclohexane-1,4-dimethylene terephthalate) (Tritan) instead of PEN. Furthermore, the fabrication processes have been optimized and simplified to improve the optical and mechanical properties of the sheet. As a result, the most effective fiber content for achieving the best haze characteristics of a sample consisting of Tritan and PMP has been identified.

• 접착 및 계면
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• 제13권1호
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• pp.24-30
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• 2012

폴리아릴레이트(polyarylate, PAR) 섬유의 산 처리와 자외선 조사 처리에 의한 섬유표면의 미세구조 변화를 SEM과 AFM을 통하여 살펴보고 RMS roughness로 분석하였으며, 접촉각 측정을 하였다. 또한, PAR 섬유의 표면개질이 폴리에틸렌 나프탈레이트(polyethylene naphthalate, PEN) 수지와의 계면접착력에 어떠한 영향을 미치는지를 섬유 풀-아웃 시험(Fiber Pull-out)을 통해 분석하였다. 산처리 농도와 자외선 조사 처리 시간이 증가함에 따라 PAR 섬유의 표면에 에칭이나 크랙이 발생하면서 표면의 거칠기가 증가하는 양상을 보였으며, 물에 대한 접촉각은 감소하는 결과를 보였다. PEN 수지와의 계면접착력을 분석한 결과, 산 처리 농도의 증가와 자외선 조사처리 시간이 경과에 따라 증가하였고 특히, 산 처리 농도 pH 3, 자외선 조사 처리시간이 24 h일 때 최대 계면접착력을 보였다. 이는 섬유표면조도의 증가에 따른 섬유 표면적의 증가로, 계면에서 상호작용할 수 있는 면적이 증가하기 때문이라고 볼 수 있다.

• 접착 및 계면
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• 제18권3호
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• pp.118-126
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• 2017

천연섬유강화 복합재료에서 여러 가지 섬유표면 개질을 통해서 천연섬유와 고분자매트릭스 사이에 계면접착과 복합재료 특성을 향상시키고자 하는 많은 연구 노력이 있었다. 본 연구에서는 폐양모섬유 강화 폴리프로필렌 매트릭스 복합재료를 압축성형공정 방법으로 제조하였고, 그들의 기계적 특성 및 충격 특성을 분석하였다. 그 결과, 폐양모/폴리프로필렌 복합재료의 인장 및 굴곡 특성 그리고 충격강도는 수산화나트륨(NaOH)을 이용한 알칼리처리와 3-glycidylpropylsilane(GPS)을 이용한 실란처리와 같은 처리매체에 크게 의존하였다. 실란처리를 한 폐양모섬유를 포함한 복합재료는 알칼리처리를 한 폐양모섬유를 포함한 것보다 더 우수한 기계적 특성과 충격저항성을 나타내었다. 복합재료 파단면은 특성 증가가 폐양모섬유와 폴리프로필렌 매트릭스 사이에 계면결합의 향상에 의한 것임을 정성적으로 뒷받침해주었다.