• International Journal of Korean Welding Society
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• 제2권1호
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• pp.57-61
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• 2002

This paper presents development of a SEC(Solar Energy Concentration) utilizing the concentrated solar beam radiation for joining engineering thermoplastics such as Acrylonitrile/Butadiene/Styrene(ABS), Polycarbonate(PC) and Polymethylmethacrylate (PMMA). In addition, to study the joining of the materials, necessary experimentation with applying primer was performed. Tensile tests were conducted to determine the bond strength achieved at the specimen Joint interface. Microscopic examinations of the fractured joints were performed in order to analyze the overall bond quality. Finally, the results in terms of bond strength achieved at the joint interface and energy consumed in the process was compared with those obtained with similar thermoplastic joining technique utilizing microwave energy.

• 대한치과기공학회지
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• 제46권1호
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• pp.15-19
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• 2024

An ideal post material should have physical properties similar to those of dentin. Post materials with high elastic moduli may cause root fractures. This clinical report describes the treatment of a severely damaged tooth using a recently introduced material. Polyetherketoneketone (PEKK) is a semicrystalline high-performance thermoplastic polymer. PEKK is a promising material for custom post-and-core fabrication because of its elasticity close to that of dentin, good shock absorbance, machinability, and low cost. A laboratory scanner was used to digitize the conventional impression of a severely damaged maxillary right first molar. A custom PEKK post-and-core was designed and milled using computer-aided design and computer-aided manufacturing technology. Using the proposed technique, a custom PEKK post-and-core was fabricated accurately and human error was reduced. Restoration was luted with resin cement. Custom PEKK post-and-core restorations are a viable alternative for treating severely damaged teeth.

• Advances in nano research
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• 제14권5호
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• pp.435-442
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• 2023

Sports activities, including playing tennis, are popular with many people. As this industry has become more professionalized, investors and those involved in sports are sure to pay attention to any tool that improves athletes' performance Tennis requires perfect coordination between hands, eyes, and the whole body. Consequently, to perform long-term sports, athletes must have enough muscle strength, flexibility, and endurance. Tennis rackets with new frames were manufactured because tennis players' performance depends on their rackets. These rackets are distinguished by their lighter weight. Composite rackets are available in many types, most of which are made from the latest composite materials. During physical exercise with a tennis racket, nanocomposite materials have a significant effect on reducing injuries. Materials as strong as graphite and thermoplastic can be used to produce these composites that include both fiber and filament. Polyamide is a thermoplastic typically used in composites as a matrix. In today's manufacturing process, materials are made more flexible, structurally more vital, and lighter. This paper discusses the production, testing, and structural analysis of a new polyamide/Multi-walled carbon nanotube nanocomposite. This polyamide can be a suitable substitute for other composite materials in the tennis racket frame. By compression polymerization, polyamide was synthesized. The functionalization of Multi-walled carbon nanotube (MWCNT) was achieved using sulfuric acid and nitric acid, followed by ultrasonic preparation of nanocomposite materials with weight percentages of 5, 10, and 15. Fourier transform infrared (FTIR) and Nuclear magnetic resonance (NMR) confirmed a synthesized nanocomposite structure. Nanocomposites were tested for thermal resistance using the simultaneous thermal analysis (DTA-TG) method. scanning electron microscopy (SEM) analysis was used to determine pores' size, structure, and surface area. An X-ray diffraction analysis (XRD) analysis was used to determine their amorphous nature.

• 한국생산제조학회지
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• 제19권2호
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• pp.260-266
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• 2010

Today's consumers are looking for emotional design which can fulfill their own potential desire. Emotion varies according to individual circumstance, age, sex, culture, education, profession and so on. Automotive instrument panel design is the most important part of interior design, because it affects the impression of interior design and has the equipments for safety, entertainment and various information. Thus, this study was performed to apply emotional design to automotive instrument panel which is the most important part of automotive interior, and find the best bonding conditions to build instrument panel efficiently by comparing mechanical properties in thermoplastic resin of polyethylene (PE) adhesion. Satisfactory adhesion was executed in ultrasonic welding for the same materials of PE. The best welding conditions were found to be welding time of I second, welding pressure of 250 kPA for PE-PE welding. Dissimilar materials were adhered when adhesion and ultrasonic welding were performed at the same time.

• Elastomers and Composites
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• 제48권3호
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• pp.195-200
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• 2013

본 연구의 주요 목적은 신발 겉창 재료로 사용하기 위하여 열가소성 폴리우레탄 (TPU)의 내마모성과 습윤시의 내슬립성을 에틸렌-프로필렌-디엔 고무 (EPDM) 또는 폴리부타디엔 고무 (BR)를 블렌드하여 향상시키는 것이다. 10 wt%의 EPDM 또는 BR이 TPU에 투입되었을 때 TPU/EPDM과 TPU/BR 블렌드는 TPU보다 우수한 NBS 내마모도, 인장 물성 그리고 습윤 내슬립성을 보였다. 10 wt% 이상 투입될 때는 내마모도와 인장 물성 모두 감소하였다. 10 wt% 투입시의 내마모도와 인장물성 상승은 TPU의 상분리도 증가에 기인하는 것으로 보인다.

• Elastomers and Composites
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• 제36권2호
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• pp.86-93
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• 2001

새로운 TPE(Thermoplastic Elastomer) 블렌드 재료로서 폐 EPDM(Ethylene Propylene Diene Monomer)분말의 사용에 따른 환경문제를 해결하고, TPE의 고부가 가치화를 위하여 PP (Polypropylene)와 폐 EPDM분말을 주원료로 하고, 동방향 이축압출기(Co-rotating Twin Screw Extruder)를 사용하여 동적가교를 이루어 TPE재료를 제조하였다. TPE 재료의 인장강도, 파단신율, 탄성율 등의 물성을 향상시킬 목적으로 스크류 조합별로 폐 EPDM/PP를 블렌드하여 기계적물성을 조사하였으며, 모폴로지를 조사하였다. 스크류 조합에서는 혼련판과 역 스크류 엘리먼트의 수가 증가할수록 블렌드물의 전단력과 체류시간이 증가하여 동적가교가 증가하였다.

• 한국재난정보학회 논문집
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• 제12권3호
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• pp.242-248
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• 2016

본 논문은 GMA(SIS, Stylene Isoprene Stylene) 고분자계 수지를 기반으로 제조된 아스팔트 바인더를 사용하여 플랜트에서 제조하는 혼합물로 방수기능을 갖도록 성능을 개선한 신개념의 불투수성 아스팔트 포장의 연구를 위해 수행하였다. GMA 고분자 수지 기반의 아스팔트는 유연성과 탄성을 바탕으로 중차량의 충격에 의한 영향을 받지 않으며, 우수 시에 포트 홀의 발생과 소성변형 등 여름철 온도 변화에도 안정적이다. 새롭게 제안된 열가소성 폴리머를 사용한 아스팔트 포장재료는 방수기능은 물론 역학적 특성을 검증하기 위해 KS기준과 ASTM기준에 맞게 안정도, 흐름값, 공극률, 동적 안정도, 인장강도비, 미끄럼 저항성 실험을 하여 역학적 특성을 분석 하였다.

• 한국기계가공학회지
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• 제19권10호
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• pp.59-67
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• 2020

Polycarbonate thermoplastic composite materials are anisotropic and exhibit physical properties in the longitudinal direction. Therefore, the physical properties depend on the type and direction of reinforcements. The thermal conductivity, electrical conductivity, and resin impregnation can be controlled by adding carbon nanotubes to polycarbonate resin. However, the carbon fiber used as a reinforcing material is expensive, interfacial adhesion issues occur, and simulation values are different from actual values, making it difficult to perform mathematical analysis. However, carbon nanotubes have advantages such as light weight, rigidity, impact resistance, and reduced number of parts compared to metals. Due to these advantages, it has been applied to various products to reduce weight, improve corrosion resistance, and increase impact durability. As the content of carbon nanotubes or carbon fibers increases, the mechanical properties and antistatic and electromagnetic shielding performance improve. It is expected that the amount of carbon nanotubes or carbon fibers can be optimized and applied to various industrial products.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.144-145
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• 2006

It is well known that the aromatic polycarbonate of bisphenol A (hereafter BPA polycarbonate) possesses superior transparency, exceptional toughness, high heat resistance and mechanical properties, which allow it to be diversely used for automotive, electrical, electronic, appliance and optical industries. In this paper, polycarbonate is reviewed on not only prospects of technology but market trend from the industrial point of view. It also demonstrates the diverse applications of polycarbonates with respect to its development history.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 1999년도 추계학술발표대회 논문집
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• pp.194-197
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• 1999

고분자 복합재료는 금속에 비하여 경량, 고강도, 고탄성율 등의 장점을 가지고 있어 여러 산업에서 기존의 금속 재료를 대체할 수 있는 재료로서 그 사용이 점차 증가하고 있다[1-5]. 특히 사회적으로 환경 문제가 대두되면서 열가소성 복합재료에 대한 관심이 높아지고 있으며 이에 대한 연구가 더욱 요구되고 있다. (중략)