• 한국분말재료학회지
• /
• 제21권6호
• /
• pp.454-459
• /
• 2014

In this study, the porous ceramic filter was developed to be able to remove both dust and hazardous gas contained in fuel gas at high temperature. The porous ceramic filters were fabricated and used as a catalyst support. And the effects have been investigated such as the mean particle size, organic content and addition of foaming agent on the porosity, compressive strength and pressure drop of ceramic filters. With the increase of mean powder size and the organic content for the cordierite filter, the porosity was increased, but the compressive strength and pressure drop were decreased. From the results of the research, the optimum condition for the fabrication of ceramic filters could be acquired and they had the porosity of 58%, the compressive strength of 13.4 MPa and the pressure drop of 250 Pa. It was expected that this ceramic filter was able to be applied to the glass melting furnace, combustor, and dust/toxic gas removal filter.

• Journal of the Korean Wood Science and Technology
• /
• 제27권3호
• /
• pp.63-72
• /
• 1999

종이에 습윤강도를 부여하기 위하여 셀룰로오스 섬유를 chlorocarbamoylethyl화 한 후 이를 다시 N-chlorocarbamoylethyl화했다. Chlorocarbamoylethyl화는 알칼리 촉매하에서 아크릴 아마이드와의 반응에 의해서 제조되었으며, N-chlorocarbamoylelhyl 화는 차아염소산나트륨 첨가에 의해서 제조되었다. carbamoylelhyl 화에서는 NaOH의 농도와 온도 그리고 아크릴아마이드의 첨가량이 중요한 인자로 작용했으며, carbamoylelhyl화의 초기반응에서는 $40^{\circ}C$온도에서 그리고 알칼리와 아크랄아마이드의 첨가랑이 증가할수록 더 높은 치환도가 나타났다. N-chlorocarbamoylelhyl에 의한 가장 높은 습윤강도는 치환도 0.06에서 sheet의 건조강도에 85%에 해당하는 강도를 나타냈으며, 이를 주사전자현미경을 이용하여 N-chlorocarbamoylethyl sheel의 파단면에서 섬유간 컬합력의 증가로 인한 섬유의 절단을 관찰 할 수 있었다. 그리고, N-chlorocarbamoylelhyl sheet의 재활용을 위하여 습윤강도를 저하시키는데는 차아염소산나트륨이 효과적인 것으로 나타났다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.508-511
• /
• 2004

This study focused on the effect of autonomic microcapsules on the mechanical properties of structural material. Several types of microcapsules with healing agents were manufactured by varying agitation speed of high speed stirrer. The size distribution of microcapsules was measured by a particle size analzer. The epoxy specimens embedded with microcapsules were manufactured and the degree of cure of such epoxy specimen was measured by a differential scanning calorimetry. The tensile modulus and tensile strength in epoxy specimens embedded with microcapsules were evaluated in order to investigate the effects of microcapsules on mechanical properties of structural materials. The configuration of microcapsules and morphology of fracture surfaces for the epoxy specimen were examined by an optical microcope and a scanning electron microscope. According to the results, tensile strength of the epoxy specimen embedded with microcapsules was indicated a little reduction, but tensile modulus was not much affected on microcapsules.

• 한국인쇄학회지
• /
• 제18권1호
• /
• pp.121-139
• /
• 2000

This study is to test the possibility of applying the low-molecular weighted waste cellulase, which is produced in the process of cellulase production, to paper making. After experimenting on high-crystallized non-wood fibers with beating catalyst. I got the result that the condition for the optimal effect is temperature 40~6$0^{\circ}C$, the time 90min to 120min, pH 5.0 to 6.0, the enzyme contents 0.3% and that the effect of beating such as slight reduction of fiver viscosity, increase of water retention value(WRV) and shortening of fiber length was increased with waste cellulase. Through this process, the density, folding endurance, tensile strength and burst strength of paper was remarkably increased, which is inferred to result from the increased flexibility of fiber by individual characteristics of non-wood fiber, which was high-crystallized by penetrated low-molecular weight cellulases in the fiber.

• Bulletin of the Korean Chemical Society
• /
• 제22권12호
• /
• pp.1303-1308
• /
• 2001

A series of catalysts, NiSO4/TiO2, for ethylene dimerization was prepared by the impregnation method using aqueous solution of nickel sulfate. On the basis of the results obtained from X-ray diffraction, the addition of NiSO4 shifted the transition of TiO2 from the anatase to the rutile phase toward higher temperatures due to the interaction between NiSO4 and TiO2. Nickel sulfate supported on titania was found to be very active even at room temperature. The high catalytic activity of NiSO4/TiO2 closely correlated with the increase of acidity and acid strength due to the addition of NiSO4. It is suggested that the active sites responsible for ethylene dimerization consist of low valent nickel, Ni+, with an acid.

• 대한화학회지
• /
• 제20권3호
• /
• pp.240-243
• /
• 1976

리그닌을 알칼리로 活性化시키고 페놀 및 포름알데히드와 反應시켜 새로운 樹脂를 合成하였다. 合成된 樹脂는 木材의 接着劑로 쓸 수 있는 충분한 强度를 가졌음을 확인하였다.

• 한국염색가공학회지
• /
• 제10권6호
• /
• pp.20-26
• /
• 1998

100％ viscose rayon fabric was treated with 1,2,3,4-butanetetracarboxylic acid (BTCA) by pad-dry-cure process in the presence of various catalysts. The dimensional stability, mechanical properties and hand values of fabric treated with BTCA were investigated. The ester-crosslinking reaction was influenced by the concentration of BTCA and type of catalyst. The fabric treated with BTCA was comparable or superior to that treated with conventional crosslinking agents such as dimethyloldihydroxyethyleneurea and 4,5-dihydroxy-1,3-dimethyl-2-imidazolidinone in respect of wrinkle recovery, shrinkproof property, retention of strength, and hand values. But in yellowing of fabric, the fabric treated with BTCA was inferior to that treated with conventional crosslinking agents. The fabric treated with BTCA/sodium formate was inferior to that treated with BTCA/sodium hypophosphite in respect of WRA, but had better strength retention and whiteness.

• 한국주조공학회지
• /
• 제1권3호
• /
• pp.19-29
• /
• 1981

An emphasis has been placed on the importance of selecting a sand for furan sand process, which ie affected by the properties of sand. Investigations have been carried out to use the domestic artificial sands for the furan sand process. For laboratory investigations, the sands have been prepared and tested for chemical analysis, loss on ignition, sieve analysis, AFS grain fineness number, grain shape, PH value, acid demand, surface shape, theoretical surface area, moisture absorption, crushing durability and compressive strength and S. S. I. of molding sands. Most commercial sands have been found to be able to be used. The main requirement of the sands has been shown to be that 3 or 4 screen sands, AFS no.40-70 (or 100), of low acid demand, good surface area and good grain shape require less resin and catalyst to give an adequate strength.

• 폴리머
• /
• 제34권1호
• /
• pp.8-13
• /
• 2010

발포체의 물성은 발포체의 밀도, 사용된 폴리머의 기계적 물성과 열린 셀의 함량, 셀 크기, 셀 크기 분포, 셀 형태, 스킨층의 두께 등을 포함하는 셀 구조에 의존하며, 이러한 발포체의 밀도는 사용된 폴리머의 종류와 가교제의 농도 그리고 가공 기술 및 가공 조건과 같은 다양한 원료 물질과 가교 조건에 영향을 받는다. 본 연구에서는 폴리에스터 폴리올, MDI, 아민계 촉매, 틴계 촉매, 실리콘 유화제, 물을 기본 폴리우레탄 발포체의 조성으로 설정하였으며, 발포체에 있어서 stiff-chain 요소인 사슬 연장제의 첨가에 의하여 가교 밀도를 증가시켰다. 또한, 폴리우레탄 발포체의 기계적 물성을 높이기 위해 무기 충전제로 입자 크기와 $SiO_2$ 함량이 다른 실리카와 탈크 각각 2종류를 사용하였다. 발포체의 제조시 사슬 연장제와 무기 충전제의 종류와 함량비를 달리하면서 모듈러스, 인장 강도, 압축 강도, 경도의 물성 변화를 알아보았고, 전자현미경을 통해 셀의 크기 변화와 무기 충전제의 분포도를 관찰하였다.

• 공업화학
• /
• 제3권4호
• /
• pp.722-729
• /
• 1992

몇 종류의 산화물을 혼합하여 그 장점들이 촉매의 특성으로 나타나도록 하는 복합산화물 촉매의 한 종류로서 스피넬 구조를 이루는 Mg- 및 Bn-페라이트를 촉매로 선정하여 K 첨가에 따른 물성을 분석하고 페라이트상에서 에틸벤젠의 탈수소반응에 대하여 연구하였다. 촉매의 특성분석에는 XRD, BET법, DTA, XPS, TEM, TPD 등의 분석기법을 사용하였다. 페라이트 촉매에 대한 K 첨가 효과를 검토하기 위하여 물성을 종합적으로 분석한 결과, K는 입자의 분산도를 향상시키는 구조적 조촉매로서의 역할과 함께 전자를 공급하는 조촉매로서 작용하였으며, K의 첨가량이 증가함에 따라 산점이 중화되어 그 세기가 약해지면서 산점의 농도는 증가하였다. 반응성을 연구한 결과 페라이트 촉매에 첨가된 K는 강한 산점을 중화시켜 탈수소 반응에 적합한 세기의 산점을 형성하여 스티렌의 선택도를 일정하게 유지하였다.