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Bond Properties of FRP-concrete Interface with Nano-modified Epoxy Resin under Wet-dry Cycles
Yue Li,Xiongfei Liu,Jiaqi Li 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.4
The interface bonding properties of FRP-reinforced concrete under wet/dry conditions are studied by performing the interface bond test. The effects of the number of wet/dry cycles and FRP layers, and FRP reinforcing sequence on the efficiency of reinforcement are studied. The microstructure of FRP-concrete interface is observed by SEM. The variations in bond properties of FRP-concrete interface under extreme conditions under tension are investigated. Experimental results show at the early stage of wet/ dry cycles, the strengths of concrete and epoxy resin increase, and further interface bond strength enhances. As wet/dry cycles forward, defects and loose microstructure form in both FRP and concrete, and the interface bond strength decreases. Under identical conditions, the interface bond strength of sample strengthened by FRP after wet-dry cycles is higher than that of sample strengthened before wet-dry cycles. FRP-concrete bond strength is related to the number of wet-dry cycles.
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상아질 표면 젖음성이 수종 자가접착레진시멘트의 인장접착강도에 미치는 영향
윤성영,박세희,김진우,조경모 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.2
본 연구의 목적은 다른 표면 젖음성을 갖는 상아질에 대한 수종의 자가접착레진시멘트의 인장접착강도를 비교하고자 하는 것이다. 이번 실험을 위해 Rely-X Unicem (3M. ESPE. St. Paul. MN. USA). Embrace Wetbond (Pulpdent. Oakland. MA. USA). Maxcem (Kerr. Orangc. CA. USA) 3종의 자가접착레진시멘트를 사용하였다. 발거한 상, 하악 대구치 60 개를 미세절단기 (Acutom P-50, Struers, Copenhagen Denmark)를 이용해 한 치아에서 2 mm × 2 mm × 7 mm의 치아 시편 두개씩 얻었다. 상아질 표면을 건조 그룹은 10 초간 강한 공기로 건조시켰고, 습윤 그룹은 과잉의 수분을 2 초간 거즈로 압박해 제거하였다. 상아질 표면의 젖음성을 달리한 시편에 자가접착레진시멘트를 접착한 후 상온의 상대습도 100% 상태에서 24 시간 보관했고, 만능시험기 (EZ Test, Shimadzu corporation, Kyoto, Japan)를 이용해 인장접착강도를 측정했고, 분리된 접착면의 파절양상을 근관 치료용 현미경 (OPMI pro. Carl Zeiss. Oberkochen. Germany)을 이용해 20 배의 배율로 관찰하였다. SPSS™ Ver 10.0 (SPSS Inc.. Chicago. IL. USA)을 사용응하여 동일한 자가접착레진시멘트에서 상아질 젖음성에 따른 인장접착강도를 T-test로 비교하였으며, 각 자가접착레진시멘트간의 인장접착강도를 One way ANOVA test로 비교 분석하고 95% 유의수준에서 Scheffe's test로 사후검정 하였다. 실험 결과 자가접착레진시멘트의 인장접착강도는 상마질 젖음성에 영향을 받지 않았으며, 상아질 표면 젖음성과 상관없이 Maxcem의 인장접착강도가 Unicem과 Embrace의 인장접착강도보다 유의성 있는 낮은 값을 나타내었다. 또한 모든 시편의 분리된 접착면은 접착실패 양상을 나타내었다. 이상의 실험 결과로 볼 때 자가접착레진시멘트는 상아질 표면 젖음성에 상관없이 사용할 수 있을 것이라고 생각된다. The purpose of this study was to compare the tensile bond strength of several self-adhesive resin cements bonded to dentin surfaces with different wet conditions. Three self-adhesive resin cements:Rely-X Unicem (3M ESPE. St. Paul, MN USA). Embrace Wetbond (Pulpdent. Oakland. MA, USA). Maxcem (Kerr. Orange, CA USA) were used. Extracted sixty human molars were used. Each self-adhesive resin cement was adhered to the dentin specimens (two rectangular sticks from each molar) in different wet conditions. Tensile bond strength were measured using universal testing machine (EZ Test Shimadzu corporation Kyoto. Japan) at a crosshead speed of 1.0mm/min. After the testing bonding failures of specimens were observed by Operative microscope (OPMI pro. Carl Zeiss, Oberkochen, Germany). T-test was used to evaluate the effect of dentin surface wetness. One-way ANOVA test was used to evaluate the tensile bond strength of self-adhesive resin cements in the same condition. Scheffe's test was used for statistical analyzing at the 95% level of confidence. The result showed that wetness of dentin surface didn't affect tensile bond strength of self0adhesive resin cements and Maxcem showed the lowest tensile bond strength.
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Kim, Young Kyung,Min, Bong Ki,Son, Jun Sik,Kim, Kyo-Han,Kwon, Tae-Yub Informa Healthcare 2014 Acta odontologica scandinavica Vol.72 No.8
<P><B><I>Objective.</I></B> This study investigated the effect of different drying methods of dentin surface on the bonding efficacy of self-adhesive resin cements (SRCs). <B><I>Materials and methods.</I></B> Three SRCs (RelyX U200, RU; Maxcem Elite, ME; and BisCem, BC) and one resin-modified glass ionomer cement (RelyX Luting 2, RL) were used. The characteristics of the materials were evaluated using thermogravimetric analysis and surface roughness and contact angle measurements. Human dentin surfaces were finished with 600-grit silicon carbide paper and assigned to three groups according to these drying methods: ethanol dehydration, drying by waiting for 10 s after blot-drying and blot-drying. The four cements were used for luting composite overlays to the dried dentin. After 24 h storage at 37°C and 100% relative humidity, stick-shaped specimens with a cross-sectional area of 0.8 mm<SUP>2</SUP> were prepared and stressed to failure in tension at a crosshead speed of 0.5 mm/min (<I>n</I> = 27). Failure modes of fractured specimens were assessed by optical and scanning electron microscopy. <B><I>Results.</I></B> RL was the most hydrophilic, followed by BC and ME and then RU. All the luting cements luted to ethanol-dehydrated dentin showed zero bond strengths. For the three SRCs, drying by waiting produced higher microtensile bond strengths than blot-drying. RU showed the best bonding performance in the above two dentin conditions. RL showed significantly higher bond strength in blot-drying condition than in drying-by-waiting (<I>p</I> < 0.001). <B><I>Conclusions.</I></B> This study suggests that dentin surface moisture has a crucial effect on the bond strength of SRCs.</P>
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Sung-Hoon Yoon*,Xin-Sheng Chai 대한화학회 2006 Bulletin of the Korean Chemical Society Vol.27 No.11
The general objective of the present study was to investigate the potential application of the UV spectroscopic method for determination of the polymeric additives present in papermaking fibrous stock solutions. The study also intended to establish the surface-chemical retention model associated with the adsorption kinetics of additives on fiber surfaces. Polyamide epichlorohydrin (PAE) wet strength resin and imidazolinium quaternary (IZQ) softening agents were selected to evaluate the analytical method. Concentrations of PAE and IZQ in solution were proportional to the UV absorption at 314 and 400 nm, respectively. The time-dependent behavior of polymeric additives obeyed a mono-molecular layer adsorption as characterized in Langmuir-type expression. The kinetic modeling for polymeric adsorption on fiber surfaces was based on a concept that polymeric adsorption on fiber surfaces has two distinguishable stages including initial dynamic adsorption phase and the final near-equilibrium state. The simulation model predicted not only the real-time additive adsorption behavior for polymeric additives at high accuracy once the kinetic parameters were determined, but showed a good agreement with the experimental data. The spectroscopic method examined on the PAE and IZQ adsorption study could potentially be considered as an effective tool for the wet-end retention control as applied to the paper industry.
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Yoon, Sung-Hoon,Chai, Xin-Sheng Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.11
The general objective of the present study was to investigate the potential application of the UV spectroscopic method for determination of the polymeric additives present in papermaking fibrous stock solutions. The study also intended to establish the surface-chemical retention model associated with the adsorption kinetics of additives on fiber surfaces. Polyamide epichlorohydrin (PAE) wet strength resin and imidazolinium quaternary (IZQ) softening agents were selected to evaluate the analytical method. Concentrations of PAE and IZQ in solution were proportional to the UV absorption at 314 and 400 nm, respectively. The time-dependent behavior of polymeric additives obeyed a mono-molecular layer adsorption as characterized in Langmuir-type expression. The kinetic modeling for polymeric adsorption on fiber surfaces was based on a concept that polymeric adsorption on fiber surfaces has two distinguishable stages including initial dynamic adsorption phase and the final near-equilibrium state. The simulation model predicted not only the real-time additive adsorption behavior for polymeric additives at high accuracy once the kinetic parameters were determined, but showed a good agreement with the experimental data. The spectroscopic method examined on the PAE and IZQ adsorption study could potentially be considered as an effective tool for the wet-end retention control as applied to the paper industry.
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