• Journal of Adhesion and Interface
• /
• v.12 no.3
• /
• pp.94-98
• /
• 2011

Ballistic property of Heracron/phenol composites was evaluated as a function of polyurethane (PU) type and their loadings. First, prepregs of phenol and polyurethane were prepared by spray coating on Heracron fabric and then they were utilized to prepare composite by varying their ratio. Next, they were consolidated at $150^{\circ}C$ for 25 min at $150kg/cm^2$ pressure and then ballistic property was measured with 1.1 g FSP (22 cal). V50 was evaluated interms of polyurethane type and ratio of phenol/PU prepreg.

• Journal of Conservation Science
• /
• v.26 no.3
• /
• pp.335-340
• /
• 2010

Urethane resin applicable for the first transcription of historical site and transcription of soil layer were synthesized in order to replace the imported urethane resin, NS-10. Comparing to the NS-10, the urethane polymers showed similar penetration to wet soil and formed a stable layer of polyurethane during progress working the peeling off the polyurethane pre-product from epoxy surface of final product. The urethane resins used for the first transcription of historical site improved tensile strength, which is consistent with that of NS-10. In addition the urethane resin for transcription of soil layer was supplied with hardness that have a also same strong point as like NS-10. This property is advantage due to simplifying the transcription work of soil layer in backward. When we tested to the real ground soil as well as experimentation compressed soil with use these synthesis urethane resin, we ca get the satisfying result in penetration property and stability and these properties evaluated the resins as an advanced product serving better convenience for worker.

• Composites Research
• /
• v.24 no.6
• /
• pp.7-11
• /
• 2011

Polyurethane oligomers (PUOs) such as UA8297, UP127 and EB8200 were utilized to enhance the anti-bullet property of Dyneema$^{(R)}$/vinylester composites. First, prepregs of PUO and vinylester (XSR10) were prepared via spray coating on Dyneema$^{(R)}$ fabric at 21 % resin content (by volume). In addition, spray coating and film lamination were also carried out with a mixture of XSR10/PUO for selected PUOs. Next, the prepregs were dried at RT for 1-2 h and then at $100^{\circ}C$ for 30 min to remove the solvent and to provide partial cure when necessary. The prepregs were stacked in 24 layers and cured at $120^{\circ}C$ for 5 min under the contact pressure and for additional 25 min at 150 $kg/cm^2$. Finally, the anti-bullet properties of composite samples were evaluated by measuring $V_{50}$ with simulated fragment projectile (SFP, 17 gr). The results showed a 6.5 and 9.0 % increase of $V_{50}$ with UP127 and EB8200, respectively.

• Magazine of the Korea Concrete Institute
• /
• v.14 no.6
• /
• pp.49-54
• /
• 2002

아직까지 우리나라에서 폴리머 시멘트 콘크리트가 콘크리트와 같이 광범위하게 사용되고 있는 것은 아니지만 건설재료로서의 사용이 증가하는 추세에 있다. 폴리머 콘크리트의 제조에는 결합재로서 물이나 시멘트가 전혀 사용되지 않고 수지(resin)만을 사용한다. 각종 수지가운데 많이 이용되고 있는 것은 에폭시 수지, 불포화 폴리에스테르 수지, 우레탄 수지, 퓨란 수지 등이 있다. 그러나 원료사정이 국가마다 다르기 때문에 폴리머 콘크리트의 결합재로 사용되는 액상수지 역시 차이가 있다. 우리나라의 경우는 에폭시수지, 불포화 폴리에스테르 수지 및 우레탄 수지가 주로 사용되고 있으며, 가까운 일본의 경우는 폴리머 콘크리트의 결합재로서 워커 빌리티, 저온경화성, 내후성 등이 우수한 메타크릴산 메틸도 사용되고 있다. 또한 폴리머 모르타르 및 콘크리트의 경화반응에 방해를 주지 않도록 충전재 및 골재 등은 건조시켜 함수율이 0.5 % 이하가 되도록 사용하고 있으나, 지금은 흡수제, 가교제 등의 혼화재료가 개발되어 함수율을 3% 까지 허용하고 있으며, 지금까지 불가능하게 생각되었던 폴리머 콘크리트에 대한 레디믹스트 콘크리트(레미콘) 개발도 흥미를 끌고 있다.(중략)

• Elastomers and Composites
• /
• v.34 no.5
• /
• pp.414-422
• /
• 1999

SBR, polyurethane and epoxy latex were separately blended with ethylene-vinyl acetate(EVA) emulsion In $0{\sim}50%$. EVA emulsion was not reacted with latexes in liquid phase and mixtures had good stroage stability. The viscosity of cement mixtures was elevated to 20,000cps in $0.5{\sim}2.0$ hours by mixing. The mixtures mixed with pigment represented high viscosity and showed higher viscosity as time goes by. Mixtures had higher hardness with mixing SBR than mixing epoxy or urethane. The hardness was suddenly increased over cement content 30%. showed pencil hardness $H{\sim}2H$ in $50{\sim}60%$. The increase of hardness in high solids was depended upon not only the condensation of latexs but also the coagulation and adhesion of cement particle.

• Applied Chemistry for Engineering
• /
• v.1 no.1
• /
• pp.52-62
• /
• 1990

Cationic polycarbonate type polyurethane was prepared from the quaternization reaction of N-methyldiethanolamine(MDEA) in urethane backbone which was obtained from the reaction of polycarbonate polyol, MDI and MDEA(chain exetender). Tensile strength and modulus of the cationic urethane resins were increased sharply with increasing the ionic content in urethane backbone. But hydrolysis resistance was decreased with increasing ionic contents. The selectivity of the cationic polycabonate urethane membrane for water/ethanol separation by pervaporation was about 20. The carrier mediated transport mechanism was considered the most probable separation mechanism for these membranes.

• The monthly packaging world
• /
• s.245
• /
• pp.70-81
• /
• 2013

• Elastomers and Composites
• /
• v.33 no.5
• /
• pp.324-334
• /
• 1998

SBR, polyurethane, acryl and epoxy latex were seperately mixed with ethylene-vinylacetate emulsion(EVA) in the range of $0{\sim}50%$ (wt.% ). For the mixtures, the various physical properties were examined. The viscosity of mixtures was mainly influenced by compatability with EVA emulsion, was decreased within 20% (wt.% ) of latex content, and showed the similar values over 20% (wt.% ) of latex content. The workable time of cement mixtures was mainly depended on the reactivity with cement. The formation of film could be only within $30{\sim}40$ minutes from mixing cement. The tack-free time of mixtures was influenced by the sorts of resin and the quantity of cement. The slow order of tack-free time was epoxy mixtures>SBR mixtures>urethane mixtures>acryl mixtures. The pencil hardness of mixtures was $4B{\sim}2H$, represented higher value in cement mixtures than in emulsion state.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.3D
• /
• pp.413-420
• /
• 2011

An experiment was conducted to suggest the road pavement material combining wooden chip crushed from little useful roots and branches from logging sites or wood waste from construction sites with urethane resin. For the specimen, the mass ratio of urethane resin to construction wood waste chip/lumber waster chip was set to three different levels of 0.5, 0.75, and 1.0, which was measured, mixed with mixer, and molded; 7 days after, tensile strength test, elasticity test using golf balls and steel balls, permeability coefficient measurement, and flammability test were executed. As the result, the tensile strength of the specimen at the dry state in the air exhibited the range of 0.2-1.1MPa, and there was no change after 7 days of aging. When submerged in water, however, the strength was partially diminished; the diminishing rate was greater for less urethane resin usage, and therefore it appears desirable to set the mass ratio of resin to the wood waste chip over 0.75 to consider the moisture intrusion by precipitation and such. As the result of elasticity test, the GB and SB coefficients of the specimen using wood waste chips and urethane resin were measured to be low at below 20%, exhibiting excellent elasticity as road pavement material. Also, the permeability coefficient was over 0.5mm/sec for specimens of all combinations, exceeding the standard value required after construction for permeable pavement material, and the flammability of wood-type pavement material was evaluated to have no practical issues.

• Elastomers and Composites
• /
• v.35 no.3
• /
• pp.196-204
• /
• 2000

SBR, polyurethane, acryl and epoxy latex were separately mixed with ethylene -vinylacetate emulsion(EVA) in the range of $0{\sim}50wt%$. For the mixtures, the various physical properties such as defoamerability, mechanical property, and water resistance were experimentally examined. The excellent defoamer was BYK-021 and the appropriate use of it was 0.3 phr for the total components. The shrinkage of compounds was influenced by the compatability of resins and the formation of voids. The mechanical properties was related to the cohesive force of resin particles, the coagulation of cement particles and the co-bonding of resin particles with cement particles. Mixing latex separately showed better properties then non-mixing in the shrinkage ratio, flexural strength, adhesive strength, and impact strength. The water resistance of composites mixed with cement was worse than that of EVA resin.