• 한국가구학회지
• /
• 제17권3호
• /
• pp.87-94
• /
• 2006

The purpose of this study was to evaluate the relationships between the mixing ratio and water vapor sorption property of charcoal-based loess composites for furniture & building materials with environmental friendly. Charcoal-based loess composite can be easily made by blending method with water. But the composites had much brittle fracture pattern with the increase of charcoal content. That is due to the lack of loess that takes linkage role of composites. In water vapor sorption properties, adsorption ability of charcoal was about six times higher than that of loess. Therefore, vapor sorption ability was maximum at the mixture ratio of charcoal 80% and loess 20%. It is considered that wood charcoal based inorganic composite materials can be used for various purposes as a building interior & exterior and furniture members.

• 한국전기전자재료학회논문지
• /
• 제11권12호
• /
• pp.1060-1069
• /
• 1998

Electrical properties such as space charge accumulation and water tree length and physical properties such as tensile strength, elongation and degree of crosslinked polyethylene (XLPE)/ethylene n-butyl acrylate copolymer (EnBA) blends were investigated. It was found that electrical properties such as water tree length grown at a specific condition and AC breakdown strength are improved by blending the XLPE with EnBA. The EnBA having higher nBA content showed the better electrical properties in XLPE/EnBA blends. A further improvement of these properties was achieved when a small amount of crosslinking coagent was used in the preparation of XLPE/EnBA blends.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
• /
• pp.227-232
• /
• 2002

To evaluate the practical application of oyster shells as construction materials, an experimental study was performed. More specifically, the long-term mechanical properties and durability of concrete blended with oyster shells were investigated. Test results indicate that long-term strength of concrete blended with 10% oyster shells is almost identical to that of normal concrete. However, the long-term strength of concrete blended with 20% oyster shells Is appreciably lower than that of normal concrete. 1'hereby, concrete with higher oyster shell has the possibility giving a bad influence on the concrete long-term strength. Elastic modulus of concrete blended with crushed oyster shells decreases as the blending mixture ratio increases. Namely, the modulus is reduced by approximately 10∼15% when oyster shells are blended up to 20% replacing the fine aggregate. The drying shrinkage strain increases as the blending ratio increases. In addition, the existing model code of drying shrinkage does not coincide with the test results of this study. An adequate prediction equation needs to be developed. The utilization of oyster shells as the fine aggregate in concrete has an insignificant effect on freezing and thawing resistance, carbonation and sulfuric acid attack of concrete recycling. However, water permeability is considerably improved.

• 폴리머
• /
• 제38권4호
• /
• pp.449-456
• /
• 2014

Ternary blends of poly(L-lactic acid) (PLLA), poly(${\varepsilon}$-caprolactone) (PCL) and polyethylene oxide (PEO) were produced with different concentrations of components via melt blending. By leaching the PEO from the samples by water, porous materials were obtained with potential application for bio scaffolds. Sample porosity was evaluated by calculating the ratio of porous scaffold density (${\rho}^*$) to the non-porous material density (${\rho}_s$). Highest porosity (51.42%) was related to the samples containing 50 wt%. of PEO. Scanning electron microscopy (SEM) studies showed the best porosity resulted by decreasing PLLA/PCL ratio at constant concentration of PEO. Crystallization behavior of the ternary blend samples was studied using differential scanning calorimetry (DSC). Results revealed that the crystallinity of PLLA was improved by addition of PEO and PCL to the samples. The porosity plays a key role in governing the compression properties. Mechanical properties are presented by Gibson-Ashby model.

• 펄프종이기술
• /
• 제45권6호
• /
• pp.36-43
• /
• 2013

Effects of blending of PCC manufactured with emission gas occurred at mill on the characteristics of coating color, optical and printing properties of coated paper were investigated in order to evaluate the possibility of its use as a raw material for producing environmentally friendly coated paper. Low shear viscosity and water retention value of ground PCC 1(d50 = $6.303{\mu}m$) were higher than those of ground PCC 2(d50 = $3.149{\mu}m$). Ink set properties of ground PCC 1 and ground PCC 2 were inferior to that of PCC 3. Thus, the reducing of particle size was required in order to overcome the inferior ink set properties. Ground PCC 1 had a similar properties to clay, and it showed the possibility that ground PCC 1 could be used to produce matte grade coated papers. However, it was required to improve the stability(particle shape, particle size, and compatibility with chemicals used in coating color formulation) in the case of blending with GCC in order to keep the qualities of coated paper.

• Korean Membrane Journal
• /
• 제11권1호
• /
• pp.1-7
• /
• 2009

This work reports the preparation of proton conductive crosslinked polymer electrolyte membranes by blending poly(vinyl chloride)-g-poly(hydroxyl ethyl acrylate) (PVC-g-PHEA) and poly(vinyl alcohol) (PVA). The PHEA chains of the graft copolymer were crosslinked with PVA using sulfosuccinic acid (SA) via the esterification reaction between -OH of polymer matrix and -COOH of SA. The PVC-g-PHEA graft copolymer was synthesized via atom transfer radical polymerization (ATRP) using direct initiation of the secondary chlorines of PVC backbones. Ion exchange capacity (IEC) continuously increased with increasing concentrations of SA, due to the increasing portion of charged groups in the membrane. However, the water uptake increased up to 20.0 wt% of SA concentration above which it decreased monotonically. The membrane exhibited a maximum proton conductivity of 0.026 S/cm at 20.0 wt% of SA concentration, which is presumably due to competitive effect between the increase of ionic sites and the crosslinking reaction.

• Membrane and Water Treatment
• /
• 제6권3호
• /
• pp.205-224
• /
• 2015

A novel hydrophilic poly (vinylidene fluoride)/poly (p-phenylene terephthalamide) (PVDF/PPTA) blend membrane was prepared by in situ polycondensation of p-phenylene diamine (PPD) and terephthaloyl chloride (TPC) in PVDF solution with subsequent nonsolvent induced phase separation (NIPS) process. For comparison, conventional solution blend membrane was prepared directly by adding PVDF powder into PPTA polycondensation solution. Blend membranes were characterized by means of viscometry, X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM). The effects of different blending methods on membrane performance including water contact angle (WCA), mechanical strength, anti-fouling and anti-compression properties were investigated and compared. Stronger interactions between PVDF and PPTA in in situ blend membranes were verified by viscosity and XPS analysis. The incorporation of PPTA accelerated the demixing rate and caused the formation of a more porous structure in blend membranes. In situ blend membranes exhibited better hydrophilicity and higher tensile strength. The optimal values of WCA and tensile strength were $65^{\circ}$ and 34.1 MPa, which were reduced by 26.1% and increased by 26.3% compared with pure PVDF membrane. Additionally, antifouling properties of in situ blend membranes were greatly improved than pure PVDF membrane with an increasing of flux recovery ratio by 25%. Excellent anti-compression properties were obtained in in situ blend membranes with a stable pore morphology. The correlations among membrane formation mechanism, structure and performance were also discussed.

• 한국산림과학회지
• /
• 제76권2호
• /
• pp.119-126
• /
• 1987

본 연구는 활엽수재(闊葉樹材)인 층층나무(Cornus Controversa Hemsl), 굴참나무(Quercus variabilis Blume) 및 산벚나무(Prunus sargentii Redher)를 시험편(試驗片)으로 하여 치수안정화효과(安定化效果)를 높일 수 있는 PEG 적정분자량(分子量)과 혼합방법(混合方法)을 혼합비 I, II, III, IV 및 V 중에서 찾는데 그 목적이 있었으며 실험결과는 다음과 같았다. 1. 목재내(木材內) PEG 주입율(注入率)은 비중에 따른 영향을 받았으며 굴참나무를 제외하고 만족할만한 주입율을 나타내어 적정혼합방법은 PEG V임을 알았다. 2. PEG V용액에서의 팽윤효과(澎潤效果)는 층층나무, 산벚나무에서 높았으며, 굴참나무의 팽윤효과(澎潤效果)를 높이기 위해서는 방수성약제(防水性藥劑)의 도장(塗裝)이 필요하다. 3. PEG V용액에서 산벚나무가 82.59%로 가장 높은 항수축능(抗收縮能)을 보였고 굴참나무가 62.79%로 가장 낮은 값을 보여 주었다. 4. 활엽수재(闊葉樹材)의 치수안정화(安定化)는 PEG의 혼합방법에 따라 커다란 차이를 나타내지 않았다. 5. 이상과 같은 실험결과를 종합 분석한 결과 비중이 높은 활엽수재(闊葉樹材)의 경우에는 PEG-400과 PEG-1000으로 혼합하되 외부인자를 충분히 고려할 필요가 있다.

• 생물환경조절학회지
• /
• 제18권4호
• /
• pp.316-325
• /
• 2009

배지의 적정 수분함량과 기상율은 분화식물 생산에 있어 중요한 환경 요인들이다. 매트관수시스템에서 Ardisia 소형분화 생산에 적합한 배지의 물리성을 구명 하고자 실험을 수행하였다. 실험에 사용된 공시 작물은 산호수와 자금우였다. 피트모스 배지에 왕겨와 펄라이트를 각각 부피비로 20, 40, 60%로 혼합하였다. 배지의 총공극은 왕겨의 혼합비율이 증가함에 따라 증가하였으나, 펄라이트는 혼합비율이 증가함에 따라 감소하였으며, 왕겨와 펄라이트의 혼합비율이 증가함에 따라 기상율은 증가하였으나, 배지의 수분함량은 감소하였다. 배지의 기상율은 왕겨 혼합배지에서 펄라이트 혼합배지보다 높았으며 증가율은 왕겨혼합배지에서 더 높았다. 배지의 $CO_2$ 농도는 기상율이 증가함에 따라 감소 하였는데, 왕겨 혼합배지에서 펄라이트 혼합배지보다 $CO_2$ 농도가 더 높았다. 산호수와 자금우의 생체중과 건물중은 왕겨를 60% 혼합한 배지에서 가장 높았으나, 지상부와 지하부의 건물 비율은 가장 낮았다. 매트관수 시스템에서 Ardisia속 식물인 산호수와 자금우의 소형 분화 생산에 적합한 배지의 물리성은 총공극과 기상율, 포트용수량이 각각 82.8, 25.6, 57.2%이었다.

• 한국작물학회지
• /
• 제50권spc1호
• /
• pp.88-93
• /
• 2005

난소화성 다당류의 함량이 높은 고아미2호의 취반특성 개선 및 식미 향상을 목적으로 수행한 연구결과는 다음과 같았다. 1. 취반이 어려운 것으로 알려진 고아미2호는 가루로 1차 호화시킨 후에도 미세전분입자는 호화되지 않은 것으로 나타나 일반적인 취반방법으로는 식미개선에 어려움이 있는 것으로 나타났다. 도정에 의해서 색, 물성 및 호화특성의 변화를 살펴 보았으나 명도와 백도 이외에는 도정율에 따른 유의한 특성 변화는 없는 것으로 나타났다. 2. 상온수분흡수특성을 통해 고아미2호 최소 1시간 이상의 수침시간을 필요로 하며 관능평가를 통해 이 경우 식미가 더 양호함을 확인할 수 있었다. 3. 품종별 호화 및 취반특성을 비교해 본 결과 고아미2호의 호화개시온도가 $88^{\circ}C$로 매우 높고 일반 밥솥에서 취반할 경우 수분흡수율과 팽창용적이 적은 것으로 보아 취반 방법에 있어서 고온고압이 요구되는 것으로 나타났다. 4. 다른 품종과의 혼합을 통한 식미 혹은 물성 개선을 위해 아밀로스 함량이 다른 일품벼, 백진주, 화선찰벼를 비교한 결과 호화가 늦고 경도가 낮으며 노화특성이 양호한 백진주, 화선찰벼가 일품벼에 비해 더 적합할 것으로 예상되었고, 관능 평가를 통해 두 품종이 일품벼에 비해 전반적으로 더 양호한 것으로 나타났다.