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  • Title/Summary/Keyword: Bonding Adhesives

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Comparison of the elastic modulus among three dentin adhesives before and after thermocycling (열시효 처리에 따른 상아질 접착 계면의 탄성계수의 변화 비교)

  • Chang, Ju-Hea;Lee, In-Bog;Cho, Byeong-Hoon;Kim, Hae-Young;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.33 no.1
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    • pp.45-53
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    • 2008
  • The purpose of this study was to determine the effects on the elastic moduli of the adhesive and the hybrid layer from thermocycling. Twenty one human molars were used to create flat dentin surfaces. Each specimen was bonded with a light-cured composite using one of three commercial adhesives (OptiBond FL [OP], Clearfil SE Bond [CL], and Xeno III [XE]). These were sectioned into two halves and subsequently cut to yield 2-mm thickness specimens; one specimen for immediate bonding test without thermocycling and the other subjected to 10,000 times of thermocycling. Nanoindentation test was performed to measure the modulus of elasticity of the adhesive and the hybrid layer, respectively, using an atomic force microscope. After thermocycling, XE showed a significant decrease of the modulus in the adhesive layer (p < 0.05). Adhesives containing hydrophilic monomers are prone to hydrolytic degradation. It may result in the reduced modulus of elasticity, which leads to the mechanically weakened bonding interface.

Preparation and Characteristics of Polymer Additives for Functional Instant Adhesives (기능성 순간접착제용 중합체 첨가제의 제조 및 특성)

  • Ihm, H.J.;Ahn, K.D.;Kim, S.B.;Kim, E.Y.;Han, D.K.
    • Journal of Adhesion and Interface
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    • v.2 no.3
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    • pp.25-32
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    • 2001
  • Ethyl cyanoacrylate (ECA) is used as an instant adhesive, and it can be readily polymerized by moisture in air without any initiator and applied for industrial products and ohome use. However, pure ECA monomer is low-viscosity liquid at room temperature that flows into substrate surface. To thicken the instant adhesive, poly(methyl methacylate)(PMMA) is often added in it commercially. Another disadvantage of instant adhesive polymer is its brittleness In this study, functional polymers including PMMA for an additive of ECA were prepared to increase viscosity of the monomer and flexibility of the adhesive atthe same time The additives, P(MMA-VAc-EVE), were synthesized by radical copolymerization of MMA with VAc and EVE having low glass transition temperature (Tg). The additives were added to ECA to get functional instant adhesives. The chemical structures of the additives and ECA polymers were confirmed by 1H NMR and FTIR, and their physical and mechanical properites were also evaluated. The Tg of the obtained additives decreased with increasing the content of VAc or VAc-EVE, indicating more improved flexibility. In addition, functional instant adhesive containing the additives showed higher bonding strength than that of the existing one.

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THE EFFECT OF PRIMING ETCHED DENTIN WITH SOLVENT ON THE MICROTENSILE BOND STRENGTH OF HYDROPHOBIC DENTIN ADHESIVE (산 부식된 상아질에 대한 용매를 이용한 프라이밍이 소수성 상아질 접착제의 미세인장접착강도에 미치는 영향)

  • Park, Eun-Sook;Bae, Ji-Hyun;Kim, Jong-Soon;Kim, Jae-Hoon;Lee, In-Bog;Kim, Chang-Keun;Son, Ho-Hyun;Cho, Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.34 no.1
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    • pp.42-50
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    • 2009
  • Deterioration of long-term dentin adhesion durability is thought to occur by hydrolytic degradation within hydrophilic domains of the adhesive and hybrid layers. This study investigated the hypothesis that priming the collagen network with an organic solvent displace water without collapse and thereby obtain good bond strength with an adhesive made of hydrophobic monomers and organic solvents. Three experimental adhesives were prepared by dissolving two hydrophobic monomers, bisphenol-A-glycidylmethacrylate (Bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA), into acetone, ethanol or methanol. After an etching and rinsing procedure, the adhesives were applied onto either wet dentin surfaces (wet bonding) or dentin surfaces primed with the same solvent (solvent-primed bonding). Microtensile bond strength (MTBS) was measured at 48 hrs, 1 month and after 10,000 times of thermocycles. The bonded interfaces were evaluated using a scanning electron microscope (SEM). Regardless of bonding protocols, well-developed hybrid layers were observed at the bonded interface in most specimens. The highest mean MTBS was observed in the adhesive containing ethanol at 48 hrs. With solvent-primed bonding, increased MTBS tendencies were seen with thermo cycling in the adhesives containing ethanol or methanol. However, in the case of wet bonding, no increase in MTBS was observed with aging.

Environment-Friendly Bonding of Decorative Veneer by SIS-Based Hotmelt Pressure-Sensitive Adhesives (환경친화성 SIS계 핫멜트 점착제를 이용한 무늬목 접착)

  • Lim, Dong-Hyuk;Kim, Sumin;Park, Young-Jun;Kim, Hyun-Joong;Yang, Han-Seung
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.3
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    • pp.22-29
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    • 2006
  • The overlaid panels are important materials in interior and construction with added surface layers (PVC films, decorative paper, decorative veneer). Generally, the adhesive for decorative veneer to wood-based panel is urea-formaldehyde (UF) adhesive which cause the emission of formaldehyde during not only the manufacturing process, but also service life. In this study, environment-friendly SIS-based hotmelt pressure-sensitive adhesive (PSA) was evaluated as a adhesive for bonding a decorative veneer. The various SIS-based hotmelt PSA was blended as a function of diblock content, softening point of tackifier, tackifier content, and applied to bonding the decorative veneer.

Utilization of Waste Bone Powders as Adhesive Fillers for Plywood (합판용 접착제의 충전제로서 폐기 골분의 이용)

  • Ko, Jae Ho;Roh, JeongKwan
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.4
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    • pp.528-537
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    • 2015
  • To reuse the waste bone from restaurants or butcher houses, the possibility of using waste bone powder after cooking as a filler for wood adhesives used in manufacturing plywood was investigated. Radiata pine (Pinus radiata D. Don) plywoods were manufactured by using commonly used wood adhesives such as urea-melamine formaldehyde (UMF) resin, urea-formaldehyde (UF) resin, and phenol-formaldehyde (PF) resin and the prepared fillers from cattle bone powder, pig bone powder, and seashell powder. Plywood fabricated by using cattle bone powder, pig bone powder, and seashell powder showed weaker performance in dry and wet glue-joint shear strength and wood failure than those of the plywood with wheat flour. The result showed that it was hard to use only bone powder for the replacement of wheat flour. However, the filler mixed with wheat flour and bone powders showed equivalent dry bonding strength and better water resistance than the wheat flour, indicating that bone powders mixed with wheat flour might be used for the manufacture of plywood. When bone powders were mixed with wheat flour as adhesive fillers the shell powder showed the lowest bonding properties and there was no big difference between the cattle bone powder and the pig bone powder.

THE EFFECT OF CYANATE METHACRYLATE ON THE SHEAR BOND STRENGTHS TO DENTIN (Cyanate methacrylate가 상아질 결합강도에 미치는 영향)

  • Kim, Hyang-Kyung;Choi, Kyung-Kyu;Choi, Gi-Woon;Park, Sang-Jin
    • Restorative Dentistry and Endodontics
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    • v.32 no.3
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    • pp.236-247
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    • 2007
  • The purpose of this study was to evaluate the effects of cyanate methacylate on the shear bond strengths to bovine dentin surfaces as a dentin primers. Seven experimental adhesives were made with different mass fraction of Isocyanatoetylme-thacrylate (IEM), 40wt% HEMA (Wako Pure Chemical Industries Osaka, Japan), 0.6% camphoroquinone, 0.4% amine and ethanol as balance dentin bonding agents (0, 2, 4, 6, 8, 10, 12%) were made and applied on the surface of bovine dentin specimens of 7 experimental groups. Shear bond strengths were measured using a universal testing machine (Instro 4466). To identify the ratio and modes of cohesive failures, microscopic examinationn was performed. The ultra-structure of resin tags were observed under scanning electron microscope. The results were as follows ; 1) A higher shear bond strengths (33.62 MPa) in group 8% of Cyanate methacrylate to dentin were found, but there were no statistically significancy between Groups (p > 0.05). 2) The higher ratio of cohesive failures mode in group 2, 6, an 10% could be seen than that in any other groups. 3) A shorter resin tags were observed in all experimental groups. This could be resulted that the preventing from the cyanate methacrylate penetrate into dentin owing to reacting it with dentin collagen. Therefore the resin tags were shorter in lengths. Whether the higher bonding strengths of dentin bonding agents can be affected was not been assured with statistic results. The results indicated that the relation between tensile strengths of the dentin adhesives to bovine dentin and resin tags formed into the dentin could not affected. The main reason of increasing the shear bond strength to bovine dentin in experimental groups could not be assured.

A Study on Bracket-Adhesive Combinations in Aspect of Shear Bond Strength and Bond Failure (전단접착강도와 탈락양상을 고려한 브라켓-접착제의 선택)

  • Han, Jae-Ik;Son, Woo-Sung
    • The korean journal of orthodontics
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    • v.28 no.6 s.71
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    • pp.955-974
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    • 1998
  • The purpose of the present study was to seek bracket-adhesive combinations which have adequate bond strength with no enamel and bracket fracture. The shear bond strengths were measured, the sites of failure and the enamel damage were investigated and the peripheral sealing and adaptation between enamel surface, bonding adhesive and bracket were evaluated. 240 noncarious human premolars were divided into twenty four groups of ten teeth. Shear bond strengths of each group were determined in an universal testing machine after two days passed and the debonded specimens were inspected to determine the predominant bond failure sites. To evaluate peripheral sealing and adaption between enamel surface, adhesive and bracket, each specimen was cut longitudinally into two halves which included the midsection of the bracket, adhesive and enamel and exmined in scanning electron microscope. Six different types of brackets were bonded to the tooth with four different type of adhesives. Six different types of brackets were Image, Plastic, Crystaline, Fascination, Transcend 2000 and metal bracket and four different adhesives were No-mix, Light-Bond, OrthoLC and Superbond C&B. From this study, it may be concluded that (1) The mean shear bond strength varied from a high of 36.58 Kg (410.07 Kg/cm2) with the Fascination-Light Bond combination group to a low of 8.93 Kg (75.51 Kg/cm2) with theImage-OrthoLC combination group. When using OrthoLC as adhesive, the mean shear bond strength was significantly lower than that of other combination groups, (2) Regardless of adhesives, the mean shear bond strength of Fascination brackets was relatively high whereas Plastic and Image brackets had low shear bonding strength. The shear bond strength of Crystaline bracket and Transcend 2m was relatively equal to or lower than that of metal bracket, (3) There was a correlation between bond strength, enamel damage and bracket fracture. As the shear bond strength was increased, the rate of enamel damage and bracket fracture were increased, (4) The combination groups that use OrthoLC as adhesive were debonded in shear stress without enamel fracture and bracket fracture, whereas the combination groups that use Superbond C&B as adhesive experienced a relative high enamel fracture rate and bracket fracture rate, (5) Peripheral sealing and adaptation between enamel-adhesive-bracket were relatively good when using Light-Bond or No-mix as adhesive. Regardless of adhesives, adaptation between bracket-adhesive were relatively good in Ceramic brackets, (6) The combination groups which had adequate bonding strength with no enamel and bracket fracture were Crystaline-No mix, Crystaline-Light Bond, Crystaline-OrthoLC, metal-No mix, metal-Light Bond and metal-OrthoLC combination groups.

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A Study on Synthesis and Properties of Polyurethane Dispersion Adhesives

  • Park, Dong Kyu;Kim, Chung Gi;Park, Chan Young
    • Elastomers and Composites
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    • v.52 no.4
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    • pp.295-302
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    • 2017
  • Polyurethane dispersion (PUD) polymers were synthesized by using polyether and polyester polyol. The effect of ionomeric centers, r(NCO / OH) values, chain extender process, and chain extender types on the adhesion properties was investigated. In the case of polyether-based PUD, the ionic center, r value, chain extension process and chain extender types were not adjusted even after adjustment. In the case of polyester-based PUD, when the ionic center content was more than 2.5%, the state of adhesive strength was 2.0kgf/cm2 or more. On the other hand, the initial adhesive strength was excellent at about 1kgf/cm2 when the ionic center content was over 3.5%. When the r value was 1.3 or more, it was found that the initial bonding strength and the state of bonding strength were excellent at about 1kgf/cm2 and 2.1kgf/cm2 or higher, respectively. An IR spectrum analysis of the synthesized PUD confirmed that PUD was composed of urethane based on the N-H characteristic peak at 3340cm1 and the urethane characteristic peak at 1730cm1. Moreover, the characteristic peaks of the isocyanate (2260cm1) used in the preparation of the prepolymer were not observed. As a result, the residual -NCO was not observed, and urethane was completely synthesized.

SHEAR BOND STRENGTH OF METAL BRACKETS BONDED WITH LIGHT-CURED ADHESIVE: AN IN VITRO COMPARATIVE STUDY (광중합 접착제로 접착된 금속 브라켓의 전단접착강도에 관한 연구)

  • Chang, Young-Il;Lee, Suhng-Jin
    • The korean journal of orthodontics
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    • v.22 no.2 s.37
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    • pp.289-296
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    • 1992
  • The purpose of this study was to evaluate and compare the shear bond strengths and failure sites of metal brackets bonded with chemically cured adhesive and light-cured adhesive. 10 brackets were bonded on prepared enamel surfaces with TransbondcircledR (Unitek/3M; U.S.A.) light-cured orthodontic adhesive and another 10 brackets were bonded with Orthoone® (Bisco:U.S.A.) chemically cured orthodontic adhesive. 24 hours after bonding, the Instron universal testing machine was used to measure the shear bond strengths. The failure sites were examined under streoscopic microscope. The results were as follows: 1 . The mean shear bond strength of metal brackets bonded with light-cured adhesive was lower than that of metal brackets bonded with chemically cured adhesive, but the difference was not statistically significant (p < 0.05). 2. Regardless of the type of adhesives, the brackets were failed primarily at the bracket base-adhesive interface. 3. Bonding of metal brackets with light-cured adhesive is considered to be clinically acceptable.

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Shingled String for the High Performance Photovoltaic Module (고효율 태양광 모듈 제작을 위한 스트링 공정 최적화)

  • Jee, Hongsub;Moon, Daehan;Song, Jinho;Jeong, Chaehwan
    • Current Photovoltaic Research
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    • v.6 no.4
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    • pp.119-123
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    • 2018
  • The High Performance Module With The Shingled String Has Several Advantages Such As The Larger Active Area, Higher Open-Circuit Voltage And Smaller Cell To Module (Ctm) Loss. To Obtain Increase Of Power In Pv Shingled Module, The Detailed Condition Of Various Parameters Related To Cutting And Bonding Process Were Investigated In This Study. We Searched The Optimized Cutting Conditions Of Laser Scan Speed, The Number Of Laser-Scribing And Also Bonding Conditions Of Electrically Conductive Adhesives (Eca) By Varying Amount Of Eca, Curing Time And Curing Temperature. The Shingled Pv Module Showed 25.4W of Maxmimum Power At 60 Rpm Of Dipensing Motor Speed, 30 Seconds Of Curing Time And 140C Of Curing Temperature, Respectively.