• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3411-3420
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• 2014

Deficiencies in wear and frost resistance as well as mechanical strength constitute the main causes of equipment failure under the harsh climatic conditions of the Earth's polar regions. To improve the properties of the materials used in this equipment, nanoparticle composites have been prepared from clays such as kaolinite, hectorite, and montmorillonite in combination with polytetrafluoroethylene (PTFE) or ultrahigh molecular weight polyethylene (UHMWPE). A number of techniques have been proposed to disperse silicate particles in PTFE or UHMWPE polymer matrices, and several successful processes have even been widely applied. Polymer nanocomposites that exhibit enhanced mechanical and thermal properties are promising materials for replacing metals and glass in the equipment intended for Arctic use. In this article, we will review PTFE- and UHMWPE-based layered silicate nanocomposites.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.410-413
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• 1998

Since early of 1980's, high. performance fiber has been developed by processing of ultrahigh molecular weight polyethylene(UHMWPE). UHMWPE fibers have high strength high modulus and excellent impact properties due to the strong C-C bond. Furthermore, the specific gravity of UHMWPE fibers is less than 1.0g/$\textrm{cm}^2$, which makes it possible to produce composites that combine good mechanical properties with low specific mass. (omitted)

• The Journal of the Korean bone and joint tumor society
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• v.10 no.1
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• pp.29-33
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• 2004

A giant cell tumor (GCT) of the distal radius is not common. Curettage with bone cementation is considered as a treatment of choice but, in the case of recurrence, marked cortical disruption, or articular invasion, en bloc excision and reconstruction with proximal fibular bone graft is usual procedure. In reconstruction of en bloc resected distal radius which had recurred GCT after conservative operation, we used the ultrahigh molecular weight polyethylene (UHMWPE) liner with intramedullary rod and bone cement, because the contamination was extent in previous operation and recurrence after fibular bone graft was fearful. This article introduce our new surgical procedure.

• Proceedings of the Korean Fiber Society Conference
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• 1987.06a
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• pp.12-13
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• 1987

• KSTLE International Journal
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• v.2 no.1
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• pp.55-58
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• 2001

The most widely-used orthopaedic grade polymer bearing liner material, ultrahigh molecular weight polyethylene (UHMWPE), for the total joint arthroplasty degrades after gamma-irradiation sterilization through the progressive oxidation in a shelf and in vivo. Oxidative degradation makes UHMWPE brittle and leads to decrease in mechanical properties. In this study the relationship between post-gamma-irradiation aging time and wear of UHMWPE was investigated. Six retrieved polyethylene hip liners implanted for 3-16 years and then stored in air for 1.5-6.5 years until tests were used. Two types of pin-on-disk wear testing were conducted by the uni-directional repeat pass rotating and by the linear reciprocating stainless steel disks against stationary polyethylene pins under 4Mpa at 1Hz with bovine serum lubrication in ambient environment. Wear of retrieved polyethylene hip liners does not have direct correlation with in vivo or total aging time. Linear reciprocal sliding motion generated more remarkable wear than uni-directional repeat pass sliding motion. It indicates that kinematic motion affects very crucially on the wear of aged UHMWPE having brittle white band region.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3762-3766
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• 2013

This article examines the modification of surface properties of ultrahigh-molecular-weight polyethylene (UHMWPE) with nanoscale ceramic particles to fabricate an improved composite with butadiene-nitrile rubber (BNR). Adhesion force data showed that ceramic zeolite particles on the surface of UHMWPE modulated the surface state of the polymer and increased its compatibility with BNR. Atomic force microscopy phase images showed that UHMWPE made up the microphase around the zeolite particles and formed the evolving layer with a complex interface. The complex interface resulted in improvements in the mechanical properties of the composite, especially its low-temperature resistance coefficients, thereby improving its performance in low-temperature applications.

• Polymer(Korea)
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• v.33 no.2
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• pp.97-103
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• 2009

Ultra-high molecular weight polyethylene (UHMWPE)/functionalized-MWNT hybrid films were prepared by the solution intercalation method, using 4-cumylphenol-MWNT (CP-MWNT) as the functionalized-MWNT. The variation of the thermomechanical properties, morphology, gas permeability, and optical transparency of the hybrid films with CP-MWNT content in the range of 0$\sim$2.00 wt% were examined. The newly synthesized UHMWPE/functionalized-MWNT hybrid films were characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and a universal tensile machine (UTM). It was found that the addition of only a small amount of functionalized-MWNT was sufficient to improve the thermomechanical properties of the UHMWPE hybrid films, with maximum enhancement being observed in the CP-MWNT loading in the range 0.50 to 1.00 wt%. The maximum enhancement in the oxygen gas barrier was also found at the functionalized MWNT content of 1.00 wt%. In this work, the thermomechanical properties and gas permeability of the hybrid films were found to be better than those of pure UHMWPE.

• Tribology and Lubricants
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• v.18 no.2
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• pp.167-172
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• 2002

The wear behaviors of ultrahigh molecular weight polyethylene pins against titanium alloy and stainless steel disks moving in two different kinematic motion were investigated by conducting repeat pass rotational sliding and linear reciprocal sliding wear tests. Linear reciprocal motion wore more the polyethylene pin than did repeat pass rotational motion for both disk materials. It means that the repeated directional change of contact stresses generates more wear debris in polyethylene. For the linear reciprocal sliding tests, titanium alloy disks were damaged with some scratches after one million cycles but no surface damage was observed on the polyethylene pins. On the other hand, fur the repeat pass rotational sliding tests, all titanium alloy disks were severely abraded on the entire region of sliding track. This phenomenon can be interpreted by that stress fatigue under repeated sliding contact initiated titanium oxide layer wear particles from disk surface, and these hard particles were embedded into polyethylene pin and then they severely abraded the disk surface. From these results it can be concluded that the kinematic motion in pin-on-disk wear tests play a crucial role on the wear behaviors of UHMWPE pins against titanium alloy and stainless steef discs.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.67-71
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• 2000

The wear behaviors of ultrahigh molecular weight polyethylene pins against titanium alloy and stainless steel disks moving in two different kinematic motion were investigated by conducting repeat pass rotational sliding and linear reciprocal sliding wear tests. Linear reciprocal motion wore more the polyethylene pin than did repeat pass rotational motion for both disk materials. It means that the repeated directional change of contact stresses generates more wear debris in polyethylene. For the linear reciprocal sliding tests, titanium alloy disks were damaged with some scratches after one million cycles but no surface damage was observed on the polyethylene pins. On the other hand, for the repeat pass rotational sliding tests, all titanium alloy disks were severely abraded on the entire region of sliding track. This phenomenon can be interpreted by that stress fatigue under repeated sliding contact initiated titanium oxide layer wear particles from disk surface, and these hard particles were embedded into polyethylene pin and then they severely abraded the disk surface. From these results it can be concluded that the kinematic motion in pin-on-disk wear tests play a crucial role on the wear behaviors of UHMWPE pins against titanium alloy and stainless steel disks.

• The Journal of the Korean bone and joint tumor society
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• v.12 no.1
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• pp.9-14
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• 2006

Purpose: The proximal tibial sarcoma patients, especially in their growing ages have problems of reconstruction. This study is to devise a methodology which can circumvent this limitations. Materials and Methods: Four cases of proximal tibial osteosarcoma underwent hemiarthroplasty. The mean age was 13 years (11~15) with a mean follow-up of 64 months (47~89). The procedure consists of ultrahigh molecular weight polyethylene (UHMWPE) liner as an substitute for the joint surface and this piece was fixed to the remaining tibial bone stock with Ender nail and bone cement. Results: Final functional score was 23.5 (78.3% of control) by MSTS criteria. All the cases showed stable joint without pain. Hemiarthroplasty related complications were absent. By saving the femoral physis, expected leg length discrepancy could be minimized by this procedure. Conclusions: Hemiarthroplasty of proximal tibia can be an option in pediatric sarcoma patients.