• 한국도로학회논문집
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• 제15권1호
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• pp.1-9
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• 2013

PURPOSES: The purpose of this study is to evaluate physical properties, durability, fatigue resistance, and long-term performance of poly-urethane concrete (PU) which can be possible application of thin layer on long-span orthotropic steel bridge and to check structural stability of bridge structure. METHODS : Various tests of physical properties, such as flexural strength, tensile strength, bond strength and coefficient of thermal expansion tests were conducted for physical property evaluation using two types of poly urethane concrete which have different curing time. Freezing and thawing test, accelerated weathering test and chloride ion penetration test were performed to evaluate the effect of exposed to marine environment. Beam fatigue test and small scale accelerated pavement test were performed to assess the resistance of PU against fatigue damage and long-term performance. Structural analysis were conducted to figure out structural stability of bridge structure and thin bridge deck pavement system. RESULTS: The property tests results showed that similar results were observed overall however the flexural strength of PUa was higher than those of PUb. It was also found that PU materials showed durability at marine environment. Beam fatigue test results showed that the resistances of the PUa against fatigue damage were two times higher than those of the PUb. It was found form small scale accelerated pavement test to evaluate long-term performance that there is no distress observed after 800,000 load applications. Structural analysis to figure out structural stability of bridge structure and thin bridge deck pavement system indicated that bridge structures were needed to increase thickness of steel deck plate or to improve longitudinal rib shape. CONCLUSIONS: It has been known that the use of PU can be positively considered to thin layer on long-span orthotropic steel bridge in terms of properties considered marine environment, resistance of fatigue damage and long-term performance.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.255-256
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• 2018

In this study, to confirm the performance of gel type urethane (hereinafter referred to as urethane gel) developed for the purpose of securing waterproof stability after application by increasing compatibility with asphalt mastic film material, general urethane coating material and adhesion. As a result, gel type urethane showed "all right" in fatigue resistance test.

• Korean Chemical Engineering Research
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• 제43권2호
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• pp.305-312
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• 2005

본 연구에서는 새로운 형태의 미세 전자 소자용 절연필름으로서 사용이 기대되는 폴리우레탄이미드를 용해성 폴리이미드와 폴리우레탄의 가교에 의해 합성하여 폴리우레탄의 함량에 따른 잔류응력 및 모폴로지, 열적 특성변화에 관해 연구하였다. 기존의 폴리우레탄이미드와는 달리 가교가 가능한 말단기로서 maleic anhydride(MA)를 사용하여 용해성 폴리이미드(6FDA-ODA/MA)를 화학적 이미드화법을 사용하여 합성하였다. 여기에 폴리우레탄 전구체를 hydroxyl ethyl acrylate로 반응시켜 만들어진 폴리우레탄을 가교시킴으로써 네트워크 구조의 새로운 폴리우레탄이미드 필름을 제조한 후 thin film stress analyzer(TFSA), XRD, TGA, DMTA를 이용해 그 특성을 분석하였다. 종래의 다른 폴리우레탄이미드 합성법과는 차별화된 각각의 폴리머의 가교형 말단끼리의 결합을 유도하는 제조법을 이용하여 합성함으로써 상온에서 잔류응력 값이 폴리우레탄의 함량이 증가할수록 감소하는 것으로 나타났다. 이러한 응력 실험 결과는 고분자 주쇄 구조의 모폴로지에 의해 영향을 받는 것을 확인할 수 있었고, 열안정성 또한 기존 폴리우레탄($240^{\circ}C$)에 비해 많이 향상된 것을 확인할 수 있었다. 잔류응력 측정 온도 범위하에서 열팽창계수는 폴리우레탄의 함량이 증가함에 따라 증가하였다.

• Journal of Welding and Joining
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• 제32권4호
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• pp.20-25
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• 2014

Laser heat source was applied on 3D poly urethane model built by 3D printer and cellulous acetate for joining. A diode laser with 808nm wavelength was transmitted through the 3D model and applied on the boundary of ABS/Acetate and 3D poly urethane model. Based on the experimental result, the ABS and 3D built poly-urethane polymers was successfully joined, but the mechanical strength was not enough at the joining boundaries in the range of 6watt to 8watt of laser heat source. However, biodegradable acetate was successfully joined without damaging the 3D built model and mechanical strength was properly achieved. The optimum laser power was found between 5watt and 8watt with scanning speed of 500mm/min, 700mm/min and 1,000mm/min. Based on the SEM analysis the filling mechanism was that the applied pressure on 3D built model squeezed the fluidic thermoplastics, ABS and acetate, into the structure of 3D model. Therefore soundness of joining was strongly depending on the viscosity of thermoplastics in polymers. The developed laser process is expected to increase productivity and minimize the cost for the final products.

• 한국건축시공학회지
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• 제2권1호
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• pp.139-146
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• 2002

This study deals with the characterizing and the application like as insulation materials in the joint part in concrete surface layer and waterproofing sheet especially for roof slabs. Using steel materials and butil-rubber tape to band waterproofing sheet and concrete surface together before this waterproofing system will be applied. It can be expected to both the curability and the watertightness by coating poly-urethane 2 or 3 times with sheet surface. Therefore this waterproofing system can be possible to protect water without the damage when vapor is going out from concrete and without air pockets because of the difference temperature inside and out. This system particularly consists of air bents and elastic waterproofing sheet considering the physical damage while water can cause purely physical damage. This system is one of the most efficient ways of waterproofing system without air pocket.

• Fibers and Polymers
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• 제3권3호
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• pp.97-102
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• 2002

A series of waterbome poly(urethane-urea) anionomers were prepared from isophorone diisocyanate (IPDI), polycaprolactone diol (PCL), dimethylol propionic acid (DMPA), ethylene diamine (EDA), and triethylamine (TEA), NaOH, or Cu($(COOCH_3)_2$) as neutralizing agent. This study was performed to decide the effect of neutralizing agent type on the particle size viscosity, hydrogen bonding index, adhesive strength, antistaticity, antibacterial and mechanical properties. The particle size of the dispersions decreased in the following order: TEA based samples (T-sample), NaOH based samples (N-sample), and Cu($(COOCH_3)_2$) based sample (C-sample). The viscosity of the dispersions increased in the order of C-sample, N-sample, and T-sample. Metal salt based film samples Of and C-sample) had much higher antistaticity than TEA based sample. By infrared spectroscopy, it was found that the hydrogen bonding index (or fraction) of samples decreased in the order of T-sam-pie, N-sample, and C-sample. The adhesive strength and tensile modulus/strength decreased in the order of T-sample, N-sam-pie, and C-sample. The C-sample had strong antibacterial halo, however, T- and N-samples did not

• 반도체디스플레이기술학회지
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• 제16권3호
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• pp.87-92
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• 2017

Poly(urethane acrylate) siloxane oligomers with Interpenetrating polymer networked nanoparticles were prepared to synthesize hard coating solution by reaction with isophorone diisocyanate(IPDI) of 1, 2, 3, 4 phr. The structures and molecular weights of the synthesized solutions were characterized by IR spectroscopy and gel permeation chromatography, respectively. In the cross-cut test for the adhesion, all the solutions showed good adhesion of 5B regardless of the content of IPDI and film thickness. The addition of 1 phr IPDI resulted in the best pencil hardness. The IPDI combined siloxane hard coating solution showed more flexibility than the siloxane solution. These results will yield the improvement in the siloxane solution using for plastic display plate.

• Macromolecular Research
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• 제9권4호
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• pp.197-205
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• 2001

Platelet adhesion onto elastic polymeric biomaterials was tested in vitro by perfusing human whole blood at a shear rate of 100 sec$\^$-1/ for possible verification of mechanisms of initial platelet adhesion perfusion of blood on the polymeric substrates was performed after treatments either with or without pre-adsorption of 1% blood plasma, and either with or without residence of the protein-preadsorbed substrate in phosphate buffered solution. The surfaces employed were elastic polymers such as poly(ether urethane urea), poly(ether urethane), silicone urethane copolymer, silicone rubber and poly(ether urethane) with the anti-calcifying agent hydroxyethane bisphosphate. Each polymer surface treated was exposed in vitro to the dynamic, heparinized whole blood perfused for upto 6 min and the surface area of platelets initially adhered was measured by employing in situ epifluorescence video microscopy. The blood perfusion was performed on the surfaces treated at the following three different conditions: directly on the bare surfaces, after protein pre-adsorption and after residence in buffer for 3 days of the surfaces protein pre-adsorbed for 2 h. The effects of blood plasma pre-adsorption on the initial platelet adhesion was surface-dependent. The amount of the adsorbed fibrinogen and the surface coverage area of the adhered platelets were dependent on the surface conditions whether substrates were bare surfaces or protein pre-adsorbed ones. To test an effect of possible morphological (re)orientations of the adsorbed proteins on the initial platelet adhesion, the polymeric substrate pre-adsorbed with 1% blood plasma was immersed in phosphate buffered solution for 3 days and then exposed to physiological blood perfusion. The surface area of the platelets adhered on these surfaces was significantly different from that of the surfaces treated with protein pre-adsorption only. These results indicated that platelet adhesion was dependent on the surface property itself and pre-treatment conditions such as blood perfusion without any pre-adsorption of proteins, and blood perfusion either after protein pre-adsorption or after subsequent substrate residence in buffer of the substrate pre-adsorbed with proteins. Understanding of these results may guide for better designs of blood-contacting materials based on protein behaviors.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 추계총회 및 학술발표회 논문집
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• pp.135-139
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• 1997

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.653-656
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• 2006

It is necessary for the new material and construction concept to make up for weak point which related to high durability and finish ability to solve exposure limit of exist construction method. This paper is deal with performance test(tier load, anti abrasion, anti impact, permeability, bond test) compositive using for water reacting soft urethane and rigid urethane to improve the exist problem which are crack movement, adhesive on the wet surface, impact and abrasion by tier load. It is getting decreasing demage compare with other exist materials after test by transfer load, movement and impact.