• Magazine of the Korea Concrete Institute
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• v.8 no.3
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• pp.157-165
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• 1996

The purpose of this study is to develop the epoxy-modified mortars and concretes without hardener having a good balance between performance and cost. In this study, the epoxy-modified and concretes without and with the hardener are prepared with various polymer-cement ratios, and tested for the mechanical properties of the epoxy-modified mortars and concretes without and with the hardener. From the test results, the epoxy-modified mortars and concretes without the hardener having an excellent mechanical properties are developed at low polymer-cement ratios of 10 to 20% compared with those of conventional epoxy-modified mortars and concretes with the hardener.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.5
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• pp.84-90
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• 2020

The adhesion strength of two konds of solid propellants(primary propellant/secondary propellant) was studied by coating agent of adhesion composition composed of organic solvent, curing agent, and cure catalyst. The coating agent using FeAA, cure catalyst, resulted propellant breaking at more 0.14 wt% and interface breaking at less 0.10 wt%. The TPB cure catalyst of confirmed the result of the interface breaking immediately after curing of the secondary propellant. In addition, the coating agent using TPB was found to increase the adhesion strength between the primary propellant and the secondary propellant over time.

• Journal of the Korean Wood Science and Technology
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• v.8 no.1
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• pp.1-12
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• 1980

경화촉진제로서 염화칼슘, 경화억제제로서 수크로오즈를 처리한 포트렌트시멘트의 양생효과를 전자현미경에 의해 관찰한 결과, 경화억제제를 처리한 시멘트는 결정을 이루지 못하고 융기상태로 남아있고, 경화촉진제를 처리한 시멘트는 겔형으로 변한후 육각형의 결정을 이루는 것이 관찰되었다. 또한 시멘트-목재 복합체의 양생은 좀 다른 양상을 보이고있어 경화제가 처리된 WCC는 포플러 스리버 표면에서 작은 융기가 겔상의 표면에 많이 관찰되나 무처리는 거의 일정한 모양의 입자가 관찰되어 시멘트 경화촉진제와 억제제의 효과를 구명하였다.

• Polymer(Korea)
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• v.37 no.2
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• pp.240-248
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• 2013

The curing behaviors of diglycidyl ether of bisphenol A (DGEBA) with mercaptan hardener were studied by the comparison with amine-adduct type hardener. Curing behaviors were evaluated by DSC at dynamic and isothermal conditions. In the DSC, the dynamic experiments were based on the method of Kissinger's equation, and the isothermal experiments were fitted to the Kamal's kinetic model. Activation energy of epoxy/amine-adduct type hardener was ca. 40 kcal/mol. As the functional group of mercaptan hardener, -SH increased, on epoxy/mercaptan hardeners, the activation energies decreased from 28 to 19 kcal/mol. Epoxy/amine-adduct type hardener was initiated at $90^{\circ}C$ or higher. However, epoxy/mercaptan hardeners reduced the initiation temperatures below $80^{\circ}C$ and shortened the durations of curing reaction within 10 min. We found out that the reaction kinetics of epoxy with mercaptan hardener followed the autocatalytic reaction models, and the maximum reaction rates were shown at the conversions of 20~40%.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.37-42
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• 2016

In this study, we examined the burning rate of the uncured propellant (with and without a curing agent application) in order to inspect the process of the HTPB solid propellant. The burning rate of the uncured propellant, that did not contain the curing agent, was approximately 9.7 mm/s at 1000 psi. In relation to the curing time, the burning rate was constant. The propellant, with the curing agent application, was approximately 8.1 mm/s showed a tendency of slowing as it burned. When the cure reaction rate was low, in accordance to the time, there were small changes in burn rate. However, when the cure reaction rate was high, the difference in burning rate was increased. The burning rate of a fully-cured propellant was approximately 6.8 mm/s, which appeared to be the lowest in order.

• Journal of the Korean Geosynthetics Society
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• v.16 no.2
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• pp.131-138
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• 2017

In this study, the expansion and compressive strength tests of emergency restoration material were carried out to restore cavity causing ground subsidence. The expansion and compressive strength characteristics according to component ratio of main material - hardener and mix proportion of blowing agent - accelerator were analyzed based on the test results. As a result of the relationship of curing time - expansion ratio analyses, it confirmed that expansion ratio decreased with reduced curing time regardless of mix proportion of blowing agent - accelerator in main material, if component ratio of hardener increased. This means that component ratio of the main material - hardener had greatly affected the expansion ratio. The compressive strength characteristics of emergency restoration material confirmed that strength was affected by mix proportion of blowing agent - accelerator. Therefore, it is necessary to apply reasonable component ratio and mix proportion to consider the required injection time, expansion ratio and strength of restoration material, when emergency restoration in ground cavity is required.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.470-473
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• 2011

본 연구에서는 산업현장에서 에폭시 강화촉진제, 도로용 첨가제 등으로 많이 사용되고 있는 경화제(M.E.K)의 혼합비에 따른 자연발화 위험성을 알아보고 산업 현장의 화재 예방을 위한 기초자료로 제공하고자 하였다. M.E.K와 에포비아 수지를 각기 다른 비율로 혼합한 상태에서 시간경과에 따른 시료의 온도변화 와 유증기 발생 및 자연발화 여부를 관찰한 결과 합성수지와 경화제의 혼합시 경화제가 5% 이상으로 혼합될 경우 혼합 수지의 내부온도가 약 $40^{\circ}C$ 이상으로 상승하면서 발포 현상과 함께 다량의 유증기가 발생하였고, 유증기가 발생된 모든 조건에 대하여 자연발화 여부는 확인할 수 없었다.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.237-240
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• 2000

본 연구에서는 비스페놀 A, 에피크로로히트린을 반응시킨 에폭시 기본주제를 중심으로 경화제, 희석제, 충진제, 촉매 등을 배합하여 토목, 건축용 반고체형 에폭시 접착제를 개발하였다. 여기서 특히 에폭시 주제와 희석제의 종류 및 배합비율에 따른 기본 물성, 접착성능 등을 측정하였다. 상온 경화 특성을 측정하기 위하여 경화시 간을 측정한 결과 희석제의 종류와 관계없이 희석제의 양이 증가할수록 경화시간이 증가하고 경화온도도 증가하는 경향을 알 수 있었으며 촉매의 양이 적을 경우가 경화시간이 빠른 것을 알 수 있었다. 또한 경화 시간은 30분 내지 40분 정도로 상온에서 사용할 수 있을 것으로 기대한다. 접착력 시험 결과는 촉매의 양이 적당한 때 가장 좋은 접착력을 나타내고 희석제 중에서 HDGE의 경우가 가장 좋은 접착력을 나타내었고 희식제의 양이 증가할수록 접착력은 증가하였다. 실리카와 철분을 섞어 반고체형 에폭시 접착제를 제조한 경우 기존의 제품보다 우수한 접착력을 나타내었다. 따라서 본 연구에서 개발한 반고체형 접착제는 제조공정 코스트 등에 대한 검토와 함께 제품화하여 토목, 건축 분야의 콘크리트 균열 접착, 볼트와 콘크리트의 접합, 목재의 접합 등에 간편하게 사용될 수 있으며, 배합물질과 비율에 따라 전기전자. 토목건축, 자동차산업 등의 산업용 접착제로서 응용될 수 있을 것으로 기대된다.

• Journal of the Korean Graphic Arts Communication Society
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• v.1 no.1
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• pp.69-75
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• 1983

Among the gelatin hardness for photographic emulsion, the formal dehyde , dialdehydes, n-Methylol compounds, ketonea, carbonylic acid and carbamic acid derivatives, and s-Triazine derivatives were studied. The greater purts of hardeners formed cross-link by the reaction with ${\varepsilon}$-Amino group in the lysine and OH group in the hydroxylysine. Glutaraldehyde produced most stable cross-link due to the formation of pyridinum ion. 2.5 hexanedione and 3-hexone-2.5-dione possible to use as the ketone hardner . The sodium salt of 2.4-dichloro-6-hydroxy-S-Triazine was newly developed as the olefinic hardners for emulsion.lsion.

• Composites Research
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• v.32 no.6
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• pp.349-354
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• 2019

The Aluminum conductor composite core consists of fast-curing thermosetting epoxy used as reinforcements and carbon fiber and glass fiber used as matrix. In this study, we have investigated fast curing epoxy cured products used for composite core(Aluminum Conductor Composite Core, ACCC). Tetrafunctional epoxy(PA 806) was used as a multifunctional epoxy, along with two kinds of curing agents, MNAn(5-Methyl-5-norbornene-2,3-dicarboxylic anhydride) and HHPA(Hexahydrophthalic Anhydride), to make an epoxy cured product and their properties were evaluated. Optimum conditions are confirmed by varying the content of curing accelerator in the selected epoxy and curing agent.