• 대한화학회지
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• 제25권3호
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• pp.140-144
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• 1981

추진제 성형에 쓰이는 isophorone diisocyanate의 구조와 반응성을 EHT, DNDO/2 및 STO-3G 방법으로 고찰하였다. 반응성은 -NCO기의 탄소원자의 양전하로 결정되며, 이 화합물의 구조는 반응성이 느리고 균일한 matrix 성형이 이루어지도록 되어 있는 것을 알았다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.944-946
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• 1999

The thermal stability of the post cured epoxy-polysiloxane IPN structure was observed by using DSC and TGA. As the post curing time increased the glass transition temperature increased and the secondary exothermic peak disappeared. The thermally decomposing activation energy calculated by using Kissinger expression was 225.6 kJ/mol. The thermal stability of the grafted IPN of epoxy and silicon compound depends on the composing ratio and post curing conditions of time and temperature.

• 한국도로학회:학술대회논문집
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• 한국도로학회 2011년 춘계학술대회 논문집
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• pp.175-181
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• 2011

• 한국도로학회:학술대회논문집
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• 한국도로학회 2003년도 학술발표회 논문집
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• pp.129-136
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• 2003

• Elastomers and Composites
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• 제35권1호
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• pp.12-18
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• 2000

환경에 대한 관심과 정부의 규제 강화로 에폭시 코팅 산업 분야에서 발생되는 휘발성 유기 물질 방출을 최소화하기 위하여 꾸준히 기술 개발을 해오고 있다. 환경 친화적인 기술 개발의 일환으로 본 연구에서는 amine-epoxy adduct (AEA)형의 수용성 에폭시 경화제를 합성하였고, 그의 구조를 FT-IR, GPC, TG/DTA로 확인하였으며, 합성한 수용성 경화제를 이용하여 KER-828 그리고 KER-500과의 경화 물성을 비교 조사하였다. 실험 결과에 의하면 건조시간은 KER-828이 KER-500보다 빨랐으나 접착력 및 내 충격성은 KER-500이 우수하였다.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1613-1619
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• 2011

A hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl) glycidylether (N-MPGE) containing Co(II), Ni(II) and Cu(II) ions was prepared by curing N-MPGE and tetradentate Schiff base Co(II), Ni(II) and Cu(II) complexes. The curing polymerization reaction of N-MPGE with metal complexes as curing agents was studied. The cured samples were studied for thermal stability, chemical (acid/alkali/solvent) and water absorption resistance and homogeneity of the cured systems. The tetradentate Schiff base, 3-[(Z)-2-piperazin-1-yl-ethylimino]-1,3-dihydro indol-2-one was synthesized by the condensation of Isatin (Indole-2, 3-dione) with 1-(2-aminoethyl)piperazine (AEP). Its complexes with Co(II), Ni(II) and Cu(II) have been synthesized and characterized by microanalysis, conductivity, Uv-Visible, FT-IR, TGA and magnetic susceptibility measurements. The spectral data revealed that the ligand acts as a neutral tetradentate Schiff base and coordinating through the azomethine nitrogen, two piperazine nitrogen atoms and carbonyl oxygen.

• 한국농공학회논문집
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• 제46권6호
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• pp.13-19
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• 2004

This study was performed to evaluate permeable properties of eco-concrete using soil, natural coarse aggregate, soil compound and polypropylene fiber. The fIexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were increased with increasing the content of coarse aggregate, soil compound and polypropylene fiber. The flexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were 259 MPa, 3,527 m/s and 275 ${\times}$ 102 MPa at the curing age of 28 days, respectively. The coefficient of permeability was decreased with increasing the content of coarse aggregate and soil compound, but it was increased with increasing the content of polypropylene fiber. Accordingly, this concrete can be used for farm road.

• 한국해양공학회지
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• 제23권5호
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• pp.54-60
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• 2009

Exposed to various environments, concrete confronts degradation by a lot of physical and chemical reaction. Though so many experiments and theorizations on the single condition of concrete degradation have been carried out by constant studies, the truth for now is that there are few studies on the compound phenomenon of degradation related with marine environments. Accordingly, this study measured the degree of degradation in the change of external shape, the change of unit weight and compressive strength, ultrasonic velocity test, and the change of length, etc. after exposing the specimen of cement mortar to the environment between 0 cycle and the maximum of 300 cycles under the condition of aquatic curing, freezing and thawing, and compound degradation, using mineral admixture effective for concrete degradation as a binder. The result indicated that the case of adding mineral admixture showed greater resistance than that of using OPC only, and specifically, the specimen with the additive of slag powder and three component system showed very excellent resistance to freezing and thawing, and compound degradation.

• Restorative Dentistry and Endodontics
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• 제28권4호
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• pp.326-333
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• 2003

Ormocer has organic-inorganic compound polymers. One of advantages of ormocer is reduced polymerization shrinkage. The purpose of this study was to compare the amount of contraction shrinkage of composite resins and ormocers. Additionally, the time of each material when there is no further change of contraction shrinkage was analysed. Four brands of composite resins (P-60. Surefil, Z-250 and Denfil) and two brands of ormocers (Definite and Admira) were used. 20 seconds, 40 seconds and 60 seconds of curing times were given. Contraction shrinkage of them were measured using a linometer for 80 seconds. The effect of material and curing time to contraction shrinkage at the time of 80 seconds was analysed by two-way ANOVA. The effect of time to contraction shrinkage was analysed by one-way ANOVA and the time when there was no further change of the contraction shrinkage was analysed. The results are as follows: 1. P-60, Definite, Z-250 and Denfil had no further change of contraction shrinkage from the time of 20 seconds, and Surefil and Admira had no further change of contraction shrinkage from the time of 10 seconds. 2. Statistical analysis revealed volumetric shrinkage varied among material (p<0,05). No significant difference of contraction shrinkage among different curing times was found, and there was no effect of interaction between materials and curing times to contraction shrinkage. 3. Definite and Admira showed the statistically same contraction shrinkage with those of Z-250 and P-60. which is higher than that of Surefil and lower than that of Denfil (p<0.05).

• 한국건축시공학회지
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• 제19권4호
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• pp.299-306
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• 2019

최근 구조물 보수보강 사례가 증가되고 있으나 보수용 모르타르의 속경성 부족에 의해 긴급공사의 어려움이 발생되고 있어 모르타르의 급결성을 증대시키고자 AL, AF, CA 급결제와 양생조건을 달리한 강도특성을 검토하였다. 그 결과 경화성상에 있어 CA 시험체가 가장 우수하였으며, 양생조건의 경우 재령 초기에서는 수중양생에서 압축강도가 다소 높아지는 경향을 보였으나 28일에서는 큰 차이가 없었다. 특히, CA 시험체에서 Ettringite생성물이 다량으로 관찰되고 있어, 광물계 급결제의 공극충진 효과에 의한 공극량 감소로 압축강도가 증가하는 것으로 판단된다.