• Polymer Science and Technology
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• v.2 no.2
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• pp.99-104
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• 1991

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.540-544
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• 2011

Novel phosphrous flame retardant tetramethylene bis(orthophosphorylurea) (TBPU) was synthesized by the reaction of diphosphoric acid with 1,4-butanediol and urea, and charaterized by Fourier transform infrared spectroscopy (FT-IR). As the amount of TBPU added in polyurethane foam (PUF) was increased, the flame retardancy of PUF was increased and the mechanical properties were not decreased. Also, in the flame resistance test after the reduced pressure storage, the flame retardancy of TBPU added PUF was retained. We could find out that the thermal resistance of TBPU added PUF increased compared to that of pure PUF.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.345-352
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• 2017

In this study, the effect of cryogenic liquefied natural gas leakage and loading on liquefied natural gas cargo hold is investigated to observe the performance of the polymer foam material that comprises the cryogenic insulation of the cargo hold. The primary barriers of liquefied natural gas carrier that are in contact with the liquefied natural gas will leak if damage is accumulated, owing to fluid impact loads or liquefied natural gas loading / unloading over a long period. The leakage of the cryogenic fluid affects the interior of the polymer foam, which is a porous closed cell structure, and causes a change in behavior with respect to the working load. In this study, mechanical properties of polyisocyanurate foam specimen, which is a polymer material used as insulation, are evaluated. The performance of the specimens, owing to the cold brittleness and the impregnation effects of the cryogenic fluids, are quantitatively compared and analyzed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.183-190
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• 2024

An environmentally-friendly nanocoating method that effectively adds flame retardant(FR) and gas shielding properties to combustible polymeric construction materials such as flexible polyurethane (PU) foam was studied. Naturally-driven two-dimensional(2D) nanomaterials such as graphene oxide (GO) can exhibit liquid crystalline (LC) properties in aqueous solutions, enabling uniform coatings on the various substrates including 3D-porous foams. LC phase-assisted coating serves as 3D-scaffold, facilitating the introduction of small molecules having antioxidant capabilities such as dopamine which is to form uniformly stacked FR coating. Additionally, the structural characteristics of the 2D-materials can effectively hinder the migration of toxic gases and flammable substances in the gas phase generated during combustion. This LC phase flame retardant coating technology could be a new approach to provide environmentally friendly and effective flame retardant and gas barrier properties to various types of polymeric materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.1-6
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• 2010

This study presents the preform injection molding and the blow molding of the injection stretch-blow molding process for PET bottles. The numerical analysis of the injection molding and the blow molding of a preform is considered in this paper using CAE with a view to minimize the warpage and the thickness. In order to determine the design parameters and processing conditions in injection/blow molding, it is very important to establish the numerical model with physical phenomenon. In this study, a three dimensional model has been introduced for the purpose and flow simulations of filling, post-filling and cooling process are carried out. The simulations resulted in the warpage in good agreement with the measurements. Also, from the result of numerical analysis, we appropriately predicted the warpage, deformation and thickness distribution along the product walls.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.706-713
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• 2015

Graphite foams (GFs) were prepared by adding different amounts of mesophase pitch (MP) into polyvinyl alcohol-acrylic acid (PVA-AAc) solution followed by the heat treatment. It was confirmed that the pore diameters of GFs were controlled by the slurry concentration, which was the mesophase content added in polymer solution, and their thermal conductivity and compressive strength were also controlled by porosities of GFs formed at different conditions. The resulting GFs in this study had the highest thermal conductivity of $53.414{\pm}0.002W/mK$ and compressive strength of $1.348{\pm}0.864MPa$ at 0.69 in porosity. The thermal conductivity of MP based GFs increased approximately 23 times higher than that of using isotropic pitch based GFs due to the developed graphitic structure.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.208-212
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• 2009

The nano-clay is widely used in polymer-nanocomposites due to the high aspect ratio, heat resistance and nano-scale dimension. In recent researches, the thermal and mechanical properties of polyurethane foam were improved with introducing the nano-clay. In this study, we describe the influence of ultrasonic treatment and content of nano-clay on properties of polyurethane foam. The nano-clay/polyurethane foam were characterized using their recovery time, compressive deflection, cell morphology and tensile test. The ultrasonic treatment was very effective for dispersion of nano-clay. Moreover, we found that introducing over 3 wt% of nano-clay bring the decrease of properties due to the poor dispersion. Expecially, ultrasonically treated 20A/polyurethane foam(1 wt%) showed greatly improved properties, such as homogeneous cell size and good dimension stability. We expect that our results could be applied to insulating materials for construction.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.277-278
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• 2005

미생물 고정화를 위하여 PU 폼을 세 가지 처리 방법으로 처리하였다. 플라즈마 처리, 플라즈마 유도 그라프팅, 플라즈마 유도 그라프팅 후 플라즈마로 재처리 방법을 사용하였다. 플라즈마 처리는 bacteria adhesion에 큰 효과를 주지 못하였고, 아크릴산의 플라즈마 유도 그라프팅은 adhesion을 세 배 이상 증가시켰다. Bacteria의 adhesion 성능 향상은 표면의 친수성을 증가시키고 새로운 groove나 cavity들을 형성시킴으로 가능하였다. 반면, 그라프팅 후 plasma re-treatment는 미생물 고정화를 크게 향상시키지 못하였다. SEM 관찰을 통하여 대부분의 E.coli.는 groove나 cavities라는 shear-free area에 서식함을 알 수 있었다. PU폼의 bacteria adhesion은 미생물과 고분자 표면 사이의 정전기적 인력이나 van der Waals 인 력에 의해 주로 영향을 받는다고 사료된다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.221-222
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• 2013

다양한 첨가제가 들어가는 고분자 화합물(compound)의 제조에 있어 난연 발포 보조제인 팽창흑연(Expandable Graphite, EGP)은 흡유가가 낮기 때문에 비교적 많은 양을 첨가해도 혼합(Mixing)이 잘 되는 것으로 알려져 있다. 본 논문에서는 대표적인 인계 난연제 APP(Ammonium Polyphosphate)를 사용한 난연 EPDM(Ethylene Propylene Diene Monomer) 폼에 팽창흑연 첨가량을 증가시키면서 산소 지수와 발열량을 통해 난연 성능의 변화를 분석하였다. 산소지수는 ISO 4589-2 상온 산소지수 방법을, 발열량 평가는 ISO 5660-1 콘 칼로리미터를 활용하였다.

• Composites Research
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• v.31 no.4
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• pp.122-127
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• 2018

Sandwich composites of carbon fiber reinforced plastic(CFRP) and polymer foam will be used to automobile and aerospace industry according to increasing importance of light weight. In this study, mechanical and heat resistance properties of sandwich composites were compared with type of polymer foam (polyethylene terephthalate(PET), polyvinylchloride(PVC), epoxy and polyurethane). All types of polymer foams were degraded to 30, 60, 120, 180 minutes in $180^{\circ}C$. After heat degradation, the polymer foams were observed using optical microscope and compressive test was performed using universal testing machine(UTM). Epoxy foam had the highest compressive property to 2.6 MPa and after thermal degradation, the mechanical property and structure of foam were less changed than others. Epoxy foam had better mechanical properties than other polymer foams under high temperature. Because the epoxy foam was post cured under high temperature. As the results, Epoxy foam was optimal materials to apply to structures that thermal energy was loaded constantly.