• 한국도로학회:학술대회논문집
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• 2003.10a
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• pp.169-172
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• 2003

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2005.04a
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• pp.122-131
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• 2005

• The Journal of the Convergence on Culture Technology
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• v.4 no.2
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• pp.211-216
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• 2018

Separation technology combining adsorption and membrane is expected to be applied in many fields such as water treatment. In this fusion technique, a functional carbon membrane having a carbon whisker grown on the surface of the membrane was developed to inhibit membrane fouling, which is a problem in the membrane separation process. In this study, to elucidate the mechanism of manufacturing the functional carbon membrane, the membrane was pretreated with the polymer latex of each mixing ratio and the membrane was formed by the CVD (Chemical Vapor Deposition) method. The membrane was analyzed by scanning electron microscope (SEM), CHN analyzer (Elemental Analyzer), and X-ray diffraction (XRD). As a result, the diameter and density of carbon whiskers were higher in case of polyvinyl di-chloride (PVdC): polyvinyl chloride (PVC) = 4.5: 55. It seems possible to control the diameter and density of the carbon whiskers according to the hydrogen content of the polymer latex.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.437-441
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• 2017

This study was carried out to investigate the volumetric expansion ratio and hardness of expanded graphite after coating with various resins which were used as an additive of fireproof sealant. The coating thickness of the resin, which represents the coating rate, was dependent of the drying speed of the resin and the viscosity of the resin. Therefore the coating thickness was shown as follows: polyvinyl acetate > acrylic resin > urethane resin > water soluble latex. Furthermore, the volumetric expansion ratio was as follows: urethane resin > water soluble latex > acrylic resin > polyinyl acetate and the hardness was as follows: polyvinyl acetate resin > acrylic resin > water soluble latex > urethane resin. This showed that the volume of expansion was reduced by expansion, which was not covered by coating, but significantly increased by increasing hardness and allowed it to be used as a refractory addition. According to the response surface methodology, the optimized addition amount and stirring speed of acrylic resin were 37.6 wt% and 441.4 rpm, respectively.

• Polymer(Korea)
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• v.25 no.5
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• pp.617-624
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• 2001

The core-shell composite latexes were synthesized by stage emulsion polymerization of methyl methacrylate (MMA) and styrene (St) with ammonium persulfate after preparing monomer pre-emulsion in the presence of anionic surfactant. However, in preparation of core-shell composite latex, several unexpected results are observed, such as, particle coagulation, low degree of polymerization, and formation of new particles during shell polymerization. To solve the disadvantages, We study the effect of initiator concentrations, surfactant concentrations, and reaction temperature on the core-shell structure of polymethyl methacrylate/polystyrene and polystyrene/polymethyl methacrylate. Particle size and particle size distribution were measured using particle size analyzer, and the morphology of the core-shell composite latex was determined using transmission electron microscope. Glass temperature was also measured using differential scanning calorimeter. To identify the core-shell structure, pH of the two composite latex solutions were measured.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.571-579
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• 2016

RS-LMC (Rapid Setting Latex Modified Concrete) has been widely used as repair material for bridge deck overlay or rehabilitation, because the overlaid pavement could be opened to the traffic after 3 hours of curing. Although the field performance of RS-LMC generally indicates that it has an excellent bonding to the substrate and shows a long term performance, the crack by vibration of vehicles have been happened on the overlay of bridges in technical reports. In this study, experimental research was carried out to evaluate the vibration properties of RS-LMC overlays by using P.S.T (Pavement Shaking Table). Total 12 specimens were tested and the variables are Latex-cement ratio (L/C) and amplitude of vibration. The result shows that the number of cracks and the total length of cracks are reduced as the increase of Latex-cement ratio (L/C) until 15%. And the crack occurs at a very small strain than the proposed values by Walter, D, G and design codes.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.990-997
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• 1994

The vulcanized NR and blend films were prepared with mixing of natural rubber latex (NRL) and methyl methacrylated grafted latex(MGL) with various additives by dipping process. It was investigated the basic properties of vulcanized NR films that is optimum condition of the mature time, swelling degree, cure time at $110^{\circ}C$, and measured the mechanical properties of tensile strength and elongation of its condition. In order to identify the surface structure and the slip properties of blend films contact angles and static and kinetic friction coefficient were measured. Contact angles were decreased with increment of blend ratio of MGL, and static and kinetic friction coefficient were decreased rapidly for the NR/MG and NR-d-MG films than for the NR films. From the results, NR/MG and NR-d-MG films has slip's reinforcement in skin contact surface with increased of blend ratio of MGL.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.691-697
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• 1996

The NR films were prepared with mixing of natural rubber latex(NRL) with various additives, and NR/CR films were prepared by blend ratio of chloroprene rubber latex(CRL). The swelling degree and the mechanical properties of these films were measured according to the procure time. As a result, optimum condition were showed the swelling degree : 80~85%, precure time : 48~60hrs., and tensile strength was reduced but elongation was increased as increasing the blend ratio of CRL. On the mechanical properties of films prepared by different dipping process in these optimum condition, the tensile strength and tear strength of NR/CR films by one dipping process are better than NR-d-CR films by two dipping process. The surface of these films were observed with scanning electron microscopy(SEM). It was found that phase separation was occured as increasing the blend ratio of CRL.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.77-84
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• 2010

Latex modified concrete (LMC) exhibits improved material properties including high tensile strength and durability compared with conventional concrete, and hence LMC has been used as protective layers over the bridge deck slabs to increase their service life with underlying assumption of excellent bond behavior between the LMC overlay and the concrete substrate. In this study, the effect of the primary parameters of the concrete substrate (i.e., shrinkage, stiffness and cracking capacity) as well as the LMC overlay thickness on the probability of cracking of the bridge deck slabs using LMC overlays was investigated by carrying out the finite element analysis that simulated the bond behavior of LMC overlays on normal strength concrete (NSC) and HPC bridge deck slabs. Based on the results of the numerical analysis, it is concluded that the relatively high shrinkage strains and stiffness of HPC slabs can increase its probability of cracking in bridge deck slabs using LMC overlay.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.445-451
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• 2019

In this study, we evaluated the durability of concrete produced with recycled polymer that could replace synthetic polymer, which is the main raw material of bridge deck concrete pavement. As a result of the slump and air content test, the requirements of the Korea Highway Corporation Standard were satisfied with all mixing conditions. The slump was lowered when incorporating the recycled bio-polymer, compared to other mix proportions concrete. In contrast, the compressive strength was increased by 6.3~24.4% when the recycled bio-polymer was mixed, compared to the concrete produced with synthetic polymer. It should be noted that the compressive strength was lowered when synthetic polymer was added to concrete mixture. Durability test results showed the best durability when incorporating synthetic polymer. The durability of concrete also increased as the amount of recycled bio-polymer increased, however, the impact was slightly smaller than that of synthetic polymer.