• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.39-44
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• 2016

This study was to investigate the characteristics of combustion toxic gases of pinus rigida specimens treated with chemical additives such as pyrophosphoric acid (PP)/ammonuium ion ($NH_4{^+}$), methylenepiperazinomethyl-bis-phosphonic acid (PIPEABP) and $PIPEABP/NH_4{^+}$. Each pinus rigida plates was painted in three times with 15 wt% of each chemical additives in the aqueous solution. After drying these specimens at room temperature, the production of combustion gases and smoke was examined by the cone calorimeter (ISO 5660-1). As a result, the peak mass loss rate time (PMLR time) treated with chemicals was delayed upto 10.5~47.4% compared to that of using untreated specimen. In addition, the peak production of carbon monoxide ($CO\;_{peak}$) of 32.1~71.4% and total smoke release rate (TSRR) of 15.6~43.6% for test pieces treated with the chemical additive were higher than that of using the virgin plate. In particular, for the specimens treated with the chemical additive, the rate of smoke release (RSR) 29.4~41.5% was obtained higher than that of untreated plate except the specimen treated with $PP/4NH_4{^+}$. It can thus be concluded that the treatment using the chemical additive could partially increase the combustion-retardation properties of the species when compared to those of the virgin plate.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.671-674
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• 2009

본 논문에서는 Base resin으로 열가소성 고분자인 PPS(Poly(phenylene sulfide))를 사용하였으며, 물리적 및 화학적 특성을 증대시키기 위해 주 첨가제로는 Expanded graphite와 보조 첨가제로 Glass fiber와 Carbon fiber를 사용하여 2가지의 복합 소재를 제조 하였다. 제조한 복합소재를 활용하여 최적의 사출 조건(사출 압력, 가열시간, 금형온도 등)으로 사출을 하였으며, 각각의 최종 시편을 four point probe 장치를 사용하여 전기전도도를 측정 비교 하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.212-212
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• 2008

에폭시 수지는 화학적 열적 안정성과 절기 절연성 및 기계적 특성 등 여러 가지 우수한 특성에도 불구하고 난연성은 그 단독으로 만족시킬 수 없기 때문에 난연제를 첨가함으로써 난연효과를 얻어왔다. 기존에 할로겐 화합물인 브롬계 난연제는 우수한 난연효과에도 불구하고 연소시 유해물질이 발생되어진다. 그리하여 인계 난연제를 첨가하는 것이 고분자 시스템에 난연성을 부여하는 효과적인 수단으로 대두되어지고 있다. 이 실험에서는 인계 난연제와 브롬계 난연제를 10, 20, 30, 40wt% 첨가하여 epoxy composite 제작하였다. 제작된 epoxy composite를 UL-94V 방법으로 난연성 평가하여 브롬계 난연제 20wt%에서 V-0를 획득할 수 있었으나 인계난연제 40wt%에서도 V-0를 만족할 수 없었다. 난연제 함량에 따른 Dielelctric constant 및 loss는 브롬계 난연제를 첨가시 감소하였고, 인계난연제의 경우 증가하였다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.367-374
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• 2021

In this study, the applicability of mechanochemical process for the manufacture of self-healing admixtures and the effect of mechanochemical process on the self-healing performance were evaluated. The self-healing admixtures were adopted as a highly reactive materials(expansive agent, swelling material and crystal growth agent) for mechanochemical processes. The self-healing admixtures for the mechanochemical process application were evaluated by X-Ray Diffraction and Fourier Transform Infrared Spectroscopy analysis, water permeability performance was used to evaluate self-healing performance of mortar. As a result of the evaluation, the self-healing performance of the WM(With-Mortar)3 sample to which mechanochemical process increased by 4.1% compared to the WM1 sample that was not treated, and the average healing index was 94.3%.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.194-201
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• 2015

A lubricant used in the transport sector have been developed for the purpose of improving vehicle performance. To improve the engine oil for some terrible conditions, various studies have been conducted to improve vehicle performance. There are limitations in development of lubricant for the economic point, but various additives have beed developed in the technical point. Recently, government tried to prohibit reckless use of additives in base oil because of the environmental issues. The institutionalized quality standards of the additives has been estabilished. In this study, physicochemical properties and environmental effect of vehicle engine oils in domestic sector were investigated.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1241-1244
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• 2010

본 논문에서는 Base resin으로 열가소성 고분자인 PP(Polypropylene)를 사용하였으며, 물리적 및 화학적 특성을 증대시키기 위해 주 첨가제로는 Expanded graphite와 보조 첨가제로 Multiwall carbon nanotube를 사용하여 2가지의 복합 소재를 제조 하였다. 제조한 복합소재를 활용하여 compression molding을 하였으며, 각 함량별 시편을 four point probe 장치를 사용하여 전기전도도를 측정 비교 하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.69-74
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• 1998

Scallop, Patinopecten yessoensis (Jay), cultivated in the cold east coast of Kangwon region in Korea, is expected to be produced to about 50,000 tons in 2000 year. First of all, scallop should be exuviated to process for new goods. In this study, preservatives such s sorbate, lactate, benzoic acid, and lysozyme were to extend the shelf-life of exuviated scallop boiled with steam for 10 min. The addition of preservatives retarded the decrease in pH, and inhibited the productions of VBN, TMA, and TBA of exuviated scallop stored at $5^{\circ}C$ in the latter period of storage. They also inhibited the microbial growth, especially in the first period of storage. The estimated values of shelf-life of boiled and exuviated scallops for control, sorbate, lactate, benzoic acid, and lysozyme were about 22, 26, 29, 25, and 27 days, respectively.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.234-239
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• 2010

Carbonate derivatives were synthesized for the use of diesel additives and the derived cetane numbers of the derivatives were measured. Some carbonate ester derivatives were synthesized from 1,2-glycerol carbonate and long alkyl chain fatty acids. To improve the solubility, we introduced unsaturated groups into aliphatic carbons and alkyl group into ${\alpha}$-carbon to the carbonyl group. The derived cetane numbers obtained from ASTM method were increased up to 1.0, which means some carbonate derivatives could be potential diesel additives.

• Tribology and Lubricants
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• v.5 no.2
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• pp.32-41
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• 1989

기계 공작의 목적은 금속을 필요에 따라 새로운 형태로 가공하려는 것이다. 보통 이 과정은 공구와 가공물의 두 고체간 접촉에 의해서 이루어지게 된다. 이때 상호접촉은 금속의 소성유동이나 필요 없는 부분을 제거(절삭 가공)하도록 하므로써 새로운 형태로 만드는 과정을 의미한다. 새로운 모양을 만드는데는 높은 마찰과 높은 온도 및 공구의 마모를 동시에 수반한다. 따라서 기계공작유는 이러한 작업 과정의 효과적인 수행과 전반적인 능률에 영향을 미치게 된다. 소성 가공과정에서는 금속의 연성에 의해서 재료가 파괴됨 없이 가공물을 변형 하므로써 모양을 변화 시킨다. 여기에는 연속 과정과 불연속 상태 과정으로 구분되고 그에 따라 윤활의 목적이 다르게 된다. 기계 공작유에 관한 참고 서적은 많이 있으나, 공작유 첨가제의 화학작용과 그 기능에 관한 것은 거의 없고, 부분적인 논문은 많이 있으나 정리된 것은 많지 않아서 이 모든 자료에 의해 가공융의 첨가제에 관련된 화학 작용등 중요 사항을 구체적으로 살펴 보기로 한다.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.105-109
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• 2010

HEMA (2-hydroxyethyl methacrylate), EGDMA (ethylene glycol dimethacrylate) and propylene glycol was copolymerized in the presence of AIBN (azobisisobutyronitrile) initiator in a mould. The physical properties of the contact lens were measured. The water content of 37.06~38.71%, refractive index of 1.492~1.432, visible transmittance of 89.4~91.5%, tensile strength of 0.1416~0.2302 kgf, and contact angle of $38.60{\sim}53.53^{\circ}$ were obtained. Therefore, the contact lens material produced using propylene glycol as an additive satisfied the basic physical properties required for contact lenses application. It is interesting to note that an increase in wettability and tensile strength while having no significant changes in water content.