• 한국염색가공학회지
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• 제26권3호
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• pp.165-172
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• 2014

Novel super hydrophobic orange dyes having maximum absorption band at 450-500nm were synthesized to dye polyolefin fibers such as polypropylene and ultra high molecular weight polyethylene fibers, using 4-alkylanilines and ${\beta}$-naphthol. Their absorption spectra at visible range showed almost the same, which meant that the alkyl substituents introduced to chromophore did not affect on color appearance of the dyes. Considering both color strength and wash fastness, the decyl-substituted dye was determined as the optimum one practically. From the dyeing results at various conditions, the optimum dyeing was $130^{\circ}C$ for 1 hour with 5% owf of dyes. The good fastness ratings to washing, rubbing were obtained showing 4-5 for both fibers. Light fastness was also acceptable giving rating 3-4 for polypropylene fibers and rating 3 for ultra high molecular weight polyethylene fibers.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1570-1574
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• 2008

Various mechanical test were conducted on conventional and crosslinked ultra-high molecular weight polyethylene(UHMWPE) all prepared from the same lot of medical grade GUR 1050 for artificial joint. The conventional materials were not irradiated and treated by heating. The cosslinked materials were irradiated with $25kGy{\sim}200kGy$ by gamma-ray andthen annealed or remelted. Gamma-ray irradiation and heat treatment process were found to significantly impact the crystallinity, and hence the mechanical behavior, of the highly crosslinked UHMWPE. The radiation dose and heating conditions were key predictors of the uniaxial yielding, plastic flow, and failure properties of conventional and highly crosslinked UHMWPE. The correlation model from experiments would be the basic information to enhance the were resistance of artificial joint liner.

• 폴리머
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• 제39권1호
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• pp.23-32
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• 2015

상 전이 물질인 파라핀 왁스를 초고분자량 폴리에틸렌(UHMWPE)과의 absorption method를 통해 파우더를 제조 후 hot press를 사용하여 형태안정성 상 전이 물질(SSPCM) composite를 제조하였다. SSPCM composite의 화학, 미세구조, 형태, 열적, 결정구조, 유변학적 특성을 조사하기 위하여 FTIR, SEM, DSC, XRD, ARES 측정을 하였다. FTIR 분석결과 파라핀 및 UHMWPE의 고유 피크들이 나타나고 있는 것을 확인하였고, SEM 분석결과 파라핀의 농도가 40 wt%까지는 표면이 상당히 팽윤되며 거친 특성을 나타냄을 확인할 수 있었고, DSC 분석결과 SSPCM에서 파라핀 및 UHMWPE의 고유 융점들이 나타났고, XRD 분석에서는 파라핀과 UHMWPE의 $2{\theta}$ 값들이 SSPCM에서도 나타남을 확인할 수 있었고, ARES 분석에서는 파라핀 농도에 따른 G', G", $tan{\delta}$ 값의 변화를 확인할 수 있었다. 종합적인 분석 결과를 통해, 파라핀의 농도가 30 wt%일 때, 형태안정성 측면에서 최적의 농도임을 확인할 수 있었다.

• Tribology and Lubricants
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• 제27권6호
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• pp.293-301
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• 2011

Understanding of the tribological characteristics of polytetrafluoroethylen (PTFE) and ultra-high-molecular-weight polyethylene (UHMWPE) is crucial for their applications such as bearing and total joint replacement. In this work, the effect of the surface roughness of carbon steel on the tribological behaviors of PTFE and UHMWPE was experimentally investigated by using block-on-ring tribotester with friction force monitoring capability. It was found that that the amount of material transfer layers of PTFE formed on the carbon steel was significantly larger than those of UHMWPE, which was responsible the lower friction coefficient of PTFE. It was also concluded that the effect of surface roughness of carbon steel on the friction coefficient of UHMWPE was more significant than that of PTFE. For UHMWPE, it was found that the effect of surface roughness of counterface was varied with respect to applied normal force and sliding as well. Based on Archard's wear law, the wear coefficient of PTFE and UHMWPE was calculated to be $3{\times}10^{-5}$ ~ $8{\times}10^{-5}$ and $7{\times}10^{-6}$ ~ $2{\times}10^{-5}$, respectively.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.3-6
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• 1996

The Ultra-high molecular weight polyethylene (UHMWPE) is exclusivity used as the articulation component with metal or ceramic materials in artificial joint prosthesis because of its good mechanical properties. In the long term however, wear of UHMWPE causes complex problems and hence causes loosening of He prosthesis. In this study, we tried to enhance the wear property of UHMWPE by attaching a hydrophilic graft on the UHMWPE surface and by improving surface hardness without deteriorating the mechanical properties of UHMWPE. This was achieved by ion implantation and by ${\gamma}$-irradiation to the surface in acrylic acid solution and by photo-polymerization in divinylbenzen (DVB), diallysophthalate (DAIP) solution. The wear test was performed by a wear testing machine of ball-on-disk type devised by the authors. The UHMWPE with hydrophlic surface and increased surface hardness developed by above treatments showed less volumetric wear.

• 한국안전학회지
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• 제34권3호
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• pp.1-7
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• 2019

A variety of composite materials are applied to industries for the realization of light weight and high strength. Fiber-reinforced composites have different strength and range of application depending on the weaving method. The mechanical performance of CFRP(Carbon Fiber Reinforced Plastic) in many areas has already been demonstrated. Recently, the application of hybridization has been increasing in order to give a compensation for brittleness of CFRP. Target materials are UHMWPE (Ultra High Molecular Weight Polyethylene), which has excellent cutting and chemical resistance, so it is applied not only to industrial safety products but also to places that lining performance is expected for household appliances. In this study, the CFRP and UHMWPE of plain weave, which are highly applicable to curved products, were molded into laminated hybrid composite materials by autoclave method. The mechanical properties and the mode I failure behavior between the layers were evaluated. The energy release rate G has decreased as the initial crack length ratio increased.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권4호
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• pp.270-275
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• 2015

Purpose : UHMWPE (Ultra-high-molecular-weight-polyethylene) is one of the most widely used material in knife protection clothes because of high strength, elasticity, and light weight. The purpose of this study is to develop the accelerated life test method and predict the lifetime for the knife protection fabric composed by UHMWPE. Methods : In this study, degradation characteristics of UHMWPE fibers and knife protection fabric for cut resistance were evaluated under the hydrolysis and photo-degradation conditions. It was found out that the degradation rate of retained tensile strength was more significant in the photo-degradation than hydrolysis. Therefore, the failure time was determined as the time that the retained tensile strength in photo-degradation is less than 50%. Considering an acceleration factor for irradiance and exposure time, the lifetime was predicted from the calculated failure time. Results : As a result of the accelerated life test, the $B_{10}$ lifetime of knife protection fabric composed by UHMWPE fibers is estimated as 2.8 years for a 90% statistical confidence level. Conclusion: Since the lifetime is predicted by the view-point of radiant exposure in this study, there is a possibility that the estimated lifetime may differ from the actual lifetime. However, it is considered as an useful methodology to estimate the long-term lifetime of knife protection fabrics.

• 대한의용생체공학회:의공학회지
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• 제20권1호
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• pp.99-106
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• 1999

인공관절용 재료의 내마모성 향상을 목적으로 초고분자량 폴리에틸렌(UHMWPE)을 가교시켜 기계적 성질과 내마모성을 조사하였다. 가교제로 dicumyl peroxide(DCP)를 사용하고 가교보조제로 triallyl cyanurate(TAC)를 사용하여 용융상태에서 UHMWPE를 가교시켰다. DCP와 TAC의 함량이 증가할수록 가교된 초고분자량 폴리에틸렌(XUMPE)의 젤 함량은 증가하고 녹는점, 결정화온도, 결정화도, 인장성질은 감소하였다. Pin-on-disk 마모시험과 작은 하중을 가한 ball-on-disk 마모시험에서는 기계적 성질의 감소에도 불구하고 XUMPE의 마모부피가 UHMWPE보다 감소하였다. 이 두 시험에서의 마모는 주로 변형에 의한 것으로 판단되었으며, 마모부피는 Hertz 접촉 이론으로 계산한 최대접촉응력과 XUMPE의 항복강도의 비에 비례함을 보였다. 큰 하중을 가한 ball-on-disk 마모시험에서는 기계적 성질이 낮을수록 더 큰 마모부피를 보였으며, 마모자국의 표면거칠기와 마찰계수도 증가하였다. 이는 인장강도를 넘는 응력이 가해졌을 때 항복강도와 인장강도가 더 낮은 XUMPEDml 변형과 파괴가 촉진되기 때문으로 생각되었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.363-364
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• 2002

Although the factors that cause the failure of orthopedic implants were not clearly determined, it was reported that the shapes of wear debris affect the tribological behavior of artificial implant. Many researches were conducted to examine the wear mechanism by debris but the role of debris shape in inflammatory reaction remains unclear. To observe the debris shape by addition of reinforcement, carbon nanotubes ( CNTs ) were added to ultra high molecular weight polyethylene ( UHMWPE ) to investigate the reinforcement effect of CNTs. CNTs which have a diameter of about 10-50 nm, while their length is about 3-5 nm were produced by the catalytic decomposition of the acetylene gas using a tube furnace. Plate on disc type wear test were performed to evaluate the tribological performance of UHMWPE composites reinforced with CNTs in lubricating condition ( bovine serum ). The wear losses of CNT added UHMWPE in bovine serum were significantly reduced. Worn surface and wear debris of UHMWPE with CNTs and without CNTs were compared to investigate the reinforcement effect of CNT on tribological behavior.

• 한국염색가공학회지
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• 제27권1호
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• pp.27-34
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• 2015

Novel super hydrophobic disazo red dyes were synthesized to improve light fastness of the primary monoazo red dye of previous study on polyolefin fibers such as polypropylene and ultra high molecular weight polyethylene fibers. 4-Alkylanilines were diazotized and then coupled to 2,5-dimethylaniline to produce dye intermediates which were then further used to synthesize final disazo red dyes by diazoization and coupling to ${\beta}$-naphthol. Considering both affinity of the dyes toward both polyolefin fibers and color fastnesses, the decyl-substituted dye was determined as the optimum dye. The decyl-substituted disazo red dye exhibited good dyeability on both polyolefin fibes and almost the same color values as the previous primary monoazo red dye. Light fastness on ultra high molecular weight polyethylene fibers was improved up to rating 3~4 compared to rating 2~3 of the previous primary monoazo red dye.