• Journal of Technologic Dentistry
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• v.35 no.2
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• pp.137-142
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• 2013

Purpose: This study was to observe the surface and interfacial characteristic of Zirconia by surface treatment. And it was observed the roughness and contact angle according to processing, and the interfacial properties by surface treatment on zirconia. Methods: The oxide formation and ion diffusion between core and veneer ceramic were determined by the X-ray Dot Mapping of EPMA(Electron probe micro analyzer). The roughness was measured by 3D Digital microscope and the contact angle according to processing of zirconia was observed using distilled water on the surface. Results: The surface roughness of the specimens Z04, Z12, Z15 was measured $0.67({\pm}0.03){\mu}m$, $0.50({\pm}0.12){\mu}m$, $0.35({\pm}0.09){\mu}m$, respectively. As results of contact angle test, Z04, Z12, Z15 of specimen group without binder treatment was measured $46.79({\pm}3.17)^{\circ}$, $57.47({\pm}4.83)^{\circ}$, $56.19({\pm}2.66)^{\circ}$, respectively. but, L04, L12, L15 of specimen group without binder treatment was measured $63.84({\pm}2.20)^{\circ}$, $66.08({\pm}0.16)^{\circ}$, $65.10({\pm}1.01)^{\circ}$, respectively. Average contact angle of L15 was measured $65.10({\pm}1.01)^{\circ}$. In X-ray Dot Mapping results, thickness of binder including Al element was measured that each of L04, L12, L15 were $20{\mu}m$, $15{\mu}m$, $10{\mu}m$. Conclusion: The more rough surface increases the wettability, but the sintered exclusive binder decreases the wettability.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.207-215
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• 2001

Plastic bonded explosive(PBX) is mainly composed of the nitramine-ploymer compositions. PBX is characterized by high velocity and pressure of detonation, low vulnerability and good thermal stability. Many important applications of PBX require the good adhesion between nitramine crystals and the binder. For PBXs as well as propellants, where good mechanical properties are of great importance, dewetting therefore must be prevented by strong adhesion between filler-binder. Adhesion depends on surface characteristics of filler and binder. In order to design for better adhesion, an understanding of the surface properties of explosive and binder is required. The surface free energies are calculated from contact angle values by the method of Kaelble. Critical surface tension of solids are calculated by Zisman plot. Critical surface tension is a useful parameter for characterizing the wettability of solid surface. In this study, HMX and 3 kinds of copolymers are selected, since they are widely used in many plastic bonded explosives. The technical objective of this investigation is to predict the interaction between filler and binder from their surface free energies.

• Geomechanics and Engineering
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• v.28 no.1
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• pp.35-48
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• 2022

The effect of discrete polypropylene fibre reinforcement on shear strength parameters, tensile properties and isotropic index of stabilized compacted residual subgrade was investigated. Composites of compacted subgrade were developed from polypropylene fibre dosage of 0%, 1%, 2.5% and 4% and 3% cement binder. Saturated compacted soil benefited from incremental fibre dosage, the mobilized friction coefficient increased to a maximum at 2.5% fibre dosage from 0.41 to 0.58 and the contribution due to further increase in fibre dosage was marginal. Binder stabilization increased the degree of isotropy for unreinforced soil at lower fibre dosage of 1% and then decreased with higher fibre dosage. Saturation of 3% binder stabilized soil decreased the soil friction angle and the degree of isotropy for both unstabilized and binder stabilized soil increased with fibre dosage. The maximum tensile stress of 3% binder stabilized fibre reinforced residual soil was 3-fold that of 3% binder stabilized unreinforced soil. The difference in computed and measured maximum tensile and tangential stress decreased with increase in fibre dosage and degree of stabilization and polypropylene fibre reinforced soil met local and international criteria for road construction subgrade.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.180-184
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• 2009

A novel set of experimental test tooling for measuring pulling and holding forces for drawbeads on binders inclined at a wide range of angles is introduced. A mechanical design featuring a single load cell, a male-female draw bead set, translation and rotation degrees of freedom, and a screw-driven clamping system has been incorporated into a standard tensile test machine. On a real time basis, restraining and holding force data with respect to draw-in displacement may be directly downloaded into a PC for data processing. The proposed experimental system represents a significant breakthrough in drawbead simulation technology due to its relatively low cost, clever design, and versatility. The system is shown to yield excellent experimental data suitable for verifying theory and numerical model predictions.

• Journal of Adhesion and Interface
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• v.21 no.4
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• pp.143-155
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• 2020

Hydrophobic Organic-Inorganic (O-I) hybrid materials prepared by sol-gel process have been widely used at functional coating fields such as coatings for anti-corrosion, anti-icing, self-cleaning, anti-reflection. The key point for fabricating hydrophobic surface is to optimize the surface energy and roughness of the coating films. There are typical processes to control the surface energy and roughness which are 'In situ fabricating', 'Pre-fluorinating/Post-roughening', 'Pre-roughening/ Post-fluorinating'. In this study, particle-binder process was used for in-situ fabrication of hydrophobic coating films. Various O-I hybrid compounds prepared using several kinds of alkoxysilane compounds were used as a binder for silica nanoparticles at particle-binder process. To study effect of fluorine content and weight ratio of particle : binder on the hydrophobicity and surface morphology, Hydrophobic coating films were prepared onto glass substrate at various content of fluorine content of O-I hybrid binder and weight ratio of particle : binder. The coating films prepared using O-I hybrid binder (GPTi-HF10) having 10 wt% of fluorine content showed the highes water contact angle (107.52±1.6°). The coating films prepared at 1:3 weight ratio of GPTi-HF10 : silica nanoparticle exhibited the highest water contact angle (130.84±1.99°).

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.219-230
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• 2000

Plastic bonded explosive(PBX) is mainly composed of the nitramine explosives, RDX, HMX, and polymer binders. When the adhesion between nitramine crystals and binder is not particularly strong and can be failed under stress, dewetting occurs rather suddenly and this leads to a significant drop in tensile strength of explosives. Mechnical property of plastic bonded explosive depends on the surface characteristics of filler and binder. In order to design for better adhesion, an understanding of the surface properties of explosive and binder is essential. In this study, 2 kinds of RDX and 4 kinds of ethylene vinyl acetate copolymers are selected, since they are widely used in many plastic bonded explosives. The technical objective of this investigation is to calculate for the surface free energy of RDX and EVA using theory of Fowkes, van Oss, Neumann approaches and Kaelble equation and to predict the interaction between filler and binder from their surface free energies.

• Polymer(Korea)
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• v.32 no.3
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• pp.276-283
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• 2008

Kind of monomer(MMA, EA, BA, St)and the monomer ratio(80/20 to 20/80) where changed in the preparation of the core shell binder, and property was improved the plasma processing. Each material changed by plasma treatment time($1{\sim}10\;s$) to change to measure the tensile strength, contact angle and adhesion peel strength for the core shell binder optimal conditions for handling the output of the surface treatment. The type of polymerization and composition of the binder is a regardless initiator of APS, the reaction temperature of $85^{\circ}C$ to 0.3 wt% of the surfactant used to indicate when the conversion rate was the highest, core shell composite particle binder got two glass temperature curves. Core shell binder after the plasma processing contact angle change is the PEA/PSt 38 percent of cases within five seconds to indicate slight decrease was a decline rapidly if not handled $0^{\circ}$ to reach. Tensile strength PSt/PMMA varies $46.71{\sim}46.27\;kg_f$/2.5 cm and adhesion strength PEA/PMMA varies $7.89{\sim}14.44\;kg_f$/2.5 cm increases. Overall, adhesion strength of core shell composite particle is in the order of order PEA>PBA>PSt for shell monomer MMA.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.22-31
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• 2002

In this paper, PVA(polyvinylalcohol), oxidized starch and SBR latex were used as binders for ink-jet printing papers, and their effects of the type and blending ratio of binders on ink-jet printing properties were compared. In case of coating color using PVA mainly used for a binder in ink-jet printing, spreading of printed letters decreased and excellent images were manifested resulting from strong hydrophilic of PVA. However, increasing solids content of coating color was somewhat limited because of the interaction of PVA and functional groups in silica as well as high molecular weight of PVA. When oxidized starch and SBR latex were mixed with PVA at desirable ratio to solve these problems, runnability in coating process was improved and good printing properties were shown. Gloss was improved when latex was used along with PVA as a binder because of the thermoplastic property of the latex. From this result, possibilities of high solids content and high gloss ink-jet printing papers were investigated.

• Journal of the Korean Geotechnical Society
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• v.39 no.7
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• pp.17-30
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• 2023

This study investigates the impact of water immersion and high temperature on the shear strength of cemented sand through direct shear tests. Standard Jumunjin sand was used and cemented with binders, such as ultra-rapid hardening cement and an epoxy aqueous solution. The binder was mixed at concentrations of 4%, 8%, or 12%. Subsequently, cylindrical cemented specimens with a diameter of 64 mm and height of 25 mm were produced using compaction. The curing period was three days, and the specimens were cured under dry air, immersion, and heating conditions. The heating condition involved subjecting the immersed specimens to a microwave oven three times for three minutes to achieve an internal temperature of approximately 90℃. Regardless of the binder type, the cohesion of the cemented sand increased with higher binder content, whereas the internal friction angle exhibited a slight increase or decrease. Compared with ultra-rapid hardening cemented sand, epoxy-cemented sand displayed an average cohesion that was five times higher and an internal friction angle that was 10° higher. Overall, irrespective of binder type, the shear strength decreased during water immersion and increased during heating. Notably, the epoxy-cemented sand exhibited a three-fold increase in cohesion and a more than 20° increase in the internal friction angle during heating.

• Polymer(Korea)
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• v.34 no.2
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• pp.89-96
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• 2010

Adhesive binders with core-shell structure of organic/organic pair were prepared by emulsion polymerization of acrylic monomers, such as methyl methacrylate(MMA), ethyl acrylate(EA), n-butyl acrylate(BA), and styrene(St). Ammonium persulfate (APS) was used as an water soluble initiator in the presence of an anionic surfactant, sodium dodecyl benzene sulfonate (SDBS). Non-woven fabric and leather were impregnated with the adhesive binder. The surface of the impregnated fabric and leather were treated with plasma technique and then kinetics analysis and mechanical properties were measured. The conversions of the polymerization of core-shell binder (MMA/EA, MMA/BA) were greater than 90%. When the core-shell binder was prepared at equimolar conditions, the increasing effect of the core-shell binder on the state peel strength of the impregnated and plasma-treated non-woven/non-woven fabric has the order of MMA/St, EA/BA, BA/MMA, EA/St, and EA/MMA. When the core-shell binder was prepared at non-equimolar conditions, the increasing effect of the core-shell binder on the state peel strength of the non-woven fabric/leather has the order of MMA/BA, BA/EA, MMA/EA, St/MMA, and EA/St.