• Nuclear Engineering and Technology
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• 제12권1호
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• pp.1-8
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• 1980

고선량율 전자가속기를 이용하여 폴리에스터/면혼방직포에 난연제 (Fyrol 76)를 그래프트 중합반응 시키는 방법의 개선을 시도하였다. 폴리에스터/면(65/35) 혼방직포에 고착시킨 난연제는 Fyrol 76을 사용하였다. 팽윤조건과 단위체와 접촉시간 및 선량율 등을 적절히 조절하므로써 섬유체 난연제를 그래프트 반응시킬 수 있었으며, 그래프트 중합반응의 수율은 방사선 선창과 선팽윤(先膨潤) 조건에 좌우되었다. 난연제로 처리한 혼방직포의 난연성 효과는 산소 지수로 측정하였다. 폴리에스터/면혼방직포에 난연제를 그래프트 중합반응 시키는 방법으로 종래에는 고온에서 두단계를 거쳐 실시하는 것이었으나 본 연구를 통하여 실온에서 단 단계로 처리토록 하는 방법을 개선하였다.

• Fibers and Polymers
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• 제6권2호
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• pp.121-126
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• 2005

Semicrystalline poly(ethylene terephthalate) (cPET)/amorphous poly(ethylene terephthalate) with isophthalic acid (aPET) blends with 100/0, 75/25, 50/50, 25/75, and 0/100 by weight ratios were dissolved in a mixture of trifluoroacetic acid (TFA)/methylene chloride (MC) (50/50, v/v) and electrospun via the electrospinning technique. Solution properties such as solution viscosity, surface tension and electric conductivity were determined. The solution viscosity slightly decreased as aPET content increased, while there was no difference in surface tension with respect to aPET composition. The characteristics of the electro spun cPET/aPET blend nonwovens were investigated in terms of their morphology, pore size and gas permeability. All these measurements were carried out before and after heat treatment for various blend weight ratios. The average diameter of the fibers decreased with increasing aPET composition due to the decrease in viscosity. Also, the morphology of the electrospun cPET/aPET blend nonwovens was changed by heat treatment. The pore size and pore size distribution varied greatly from a few nanometers to a few microns. The gas permeability after heat treatment was lower than that before heat treatment because of the change of the morphology.

• 대한산업공학회지
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• 제26권2호
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• pp.95-100
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• 2000

Presented in this paper is a scheme for constructing ball rolling blends of a non-uniform B-spline surface(NUBS) patches. Ball rolling blending is a popular technique for blending between parametric surfaces. Along the "common edge" of a pair of "base surfaces" to be blended, a sequence of "ball positions" is sampled. The radius of the ball may vary along the line. At each sampling point, a ball center point and a pair of ball contact points are computed by applying a Jacobian inversion method. Using ball contact points, the constructing scheme of blend NUBS patches consists three steps; 1) determination of intermediate control vertices; 2) determination of boundary vectors; 3) determination of B-spline control vertices. The proposed blending scheme has been tested in a Omega CAM system and found to be working satisfactorily.

• 한국의류학회지
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• 제33권7호
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• pp.1121-1127
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• 2009

This study presents an eco-friendly and one-step finishing method for modifying fiber property that reduces fiber damage in wool/polyester blend fabrics. Lipase from aspergillus oryzae is used in this experiment. The enzymatic treatment condition is optimized by measuring the relative activity of lipase depending on pH level, temperature, concentration of lipase, and treatment time. The concentration of $CaCl_2$as an activator is determined by the characteristics including whiteness, water contact angle (WCA), and dyeing property. The modified properties of lipase treated fabrics are tested for pill resistance and surface morphology. The results are described as follows: the optimum condions for lipase treatment constitute a pH level of 8.0, treatment temperature of 40$^{\circ}$$_C$, concentration of lipase at 100% (o.w.f), and a treatment time of 90 minutes. $CaCl_2$helps in raising lipase activation, and the optimum concentration is 50mM. The whiteness, wet ability, and pill resistance of lipase treated fabrics improves as compared to the control. The dyeing property of lipase treated fabrics improved by 53.5% after using the one-bath dyeing method. This means that lipase treatment can save time and cost during the dyeing process since lipase treatment modifies wool and polyester fibers. The surface of lipase treated wool fibers do not exhibit any change, however voids and cracks manifest on the surface of lipase treated polyester fibers.

• 폴리머
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• 제34권1호
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• pp.32-37
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• 2010

액정표시소자의 광배향막으로 적용하기 위하여 올리고머 신나메이트와 폴리(비닐 신나메이트) (PVCi)의 블렌드를 이용하여 그루브 패턴을 형성하고 광배향 특성을 관찰하였다. UV-vis 스펙트럼 분광계를 이용하여 자외선 조사 시간에 따른 광반응 속도를 평가한 결과 올리고머 신나메이트는 폴리(비닐 신나메이트)에 비해 빠른 반응속도를 나타내었다. 폴리(비닐 신나메이트)를 주성분으로 하여 올리고머 신나메이트를 블렌드한 경우 반응속도가 약간 향상되는 특성을 확인하였다. 올리고머 신나메이트는 높은 결정성으로 인해 표면 그루브 패턴을 단독으로 형성할 수 없었지만 폴리(비닐 신나메이트)와의 블렌드를 통하여 그루브 패턴을 형성할 수 있었으며 그루브 패턴에서도 polar plot에 의해 분자 배향성을 나타냄을 확인하였다. 올리고머 신나메이트와 고분자계 신나메이트의 블렌드를 통하여 반응속도의 향상과 박막 구조의 패턴을 형성하기에 적합함의 확인을 통해 새로운 광배향막 재료로 적용 가능함을 알 수 있었다.

• Elastomers and Composites
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• 제54권1호
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• pp.54-60
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• 2019

The rapid development of the automobile industry is an important factor that led to the dramatic development of synthetic rubber. The tread part of tire that comes in direct contact with the road surface is related to the service life of the tire. Rubber compounds used in tire treads are often blended with SBR (styrene-butadiene rubber) and BR (butadiene rubber) to satisfy physical property requirements. However, when two or more kinds of rubber are blended, phase separation and silica dispersion problems may occur due to non-uniform mixing of the rubber. Therefore, in this study, we synthesized an SBR copolymer with the same composition as that of a typical SBR/BR blend compound by controlling butadiene content during ESBR (emulsion styrene-butadiene rubber) synthesis. Subsequently, silica filled compounds were manufactured using the synthesized ESBR, and their mechanical properties, dynamic viscoelasticity, and crosslinking density were compared with those of the SBR/BR blended compound. When the content of butadiene was increased in the silica filled compound, the cure rate accelerated due to an increased number of allylic positions, which typically exhibit higher reactivity. However, the T-2 compound with increased butadiene content by synthesis less likely to show an increase in crosslink density due to poor silica dispersion. In addition, the T-3 compound containing high cis BR content showed high crosslink density due to its monosulfide crosslinking structure. Because of the phase separation, SBR/BR blend compounds were easily broken and showed similar $M_{100%}$ and $M_{300%}$ values as those of other compounds despite their high crosslink density. However, the developed blend showed excellent abrasion resistance due to the high cis-1,4 butadiene content and low rolling resistance due to the high crosslink density.

• Ocean and Polar Research
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• 제45권1호
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• pp.1-9
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• 2023

Marine microalgae have different collection methods depending on their habitat. In the case of adhesive microalgae, it is difficult to separate organisms from the substrate surface, and contamination is likely to occur during the sampling process. In this study, we analyzed the collection efficiency of adhesive microalgae using three artificial fiber materials (nylon, blend fabric, and viscose rayon). Each fiber showed different fiber diameter and pore characteristics (nylon 26.09 ㎛, blend fabric 56.6 ㎛, viscose rayon 101.3 ㎛). In addition, attached organisms were collected on the surface of artificial substrates at Bukseong Port in Incheon using each tested fiber material. After that, we investigated the population and species composition. The highest number of cells was found in nylon, which was 8 times higher than in the least collected viscose rayon material. In addition, we identified 24 microalgal species from the substrate, demonstrating that the species composition differed from that of surface water. The number of collected microalgae species varied depending on the fiber materials, with nylon containing all the adhesive microalgae. In contrast, only a few microalgae were observed in other fibers. These results suggest that, of the tested fibers, nylon material may be suitable for collecting adhesive microalgae. As a result, this study may be useful for future research on adhesive microalgae.

• 접착 및 계면
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• 제4권4호
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• pp.15-21
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• 2003

친유기화 층상실리케이트의 함량을 0.25 wt%에서 9 wt%까지 변화시켜 가며 폴리설폰과 용액 블렌드하여 폴리설폰/친유기화 층상실리케이트 나노복합체를 제조하고, 필름으로 성형하였다. 제조된 폴리설폰/친유기화 층상실리케이트 나노복합체 필름은 XRD 및 TEM을 사용하여 박리여부를 확인하였다. 표면의 morphology 변화는 SEM 및 AFM을 통하여 확인하였다. 폴리설폰 수지에 소량의 층상실리케이트 첨가시에는 표면 조도의 변화가 크게 나타나지 않으나 1.5 wt% 이상의 함량을 첨가하면 삽입만 일어난 층상실리케이트에 의해 표면 조도가 커지는 것으로 보인다. 접촉각 측정을 통한 친유기화 층상실리케이트 함량에 따른 표면 장력의 변화도 1.5 wt%의 층상실리케이트 첨가량을 경계로 하여 변화하는 현상이 나타났다. 이는 층상실리케이트의 함량에 따른 분산 효과에 의해 표면에서의 분포와 배열에 기인하는 것으로 생각된다.

• The International Journal of Costume Culture
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• 제8권1호
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• pp.23-31
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• 2005

Mechanical properties and hand evaluation of wool/acrylic(W/A) blend knits were conducted before and after repeated washing to get the optimum W/A blending ratio, which could help achieve the optimum mechanical and hand properties of the knits. The five test fabrics using the yarns with different W/A blending ratios($\%$), 100/0, 70/30, 50/50, 30/70, 0/100, were knitted. The fabrics were washed by a rotating drum type washing machine. Then, objective mechanical and hand properties were evaluated by KES-FB, Kawabata evalution system for fabric. The results are as follows: there was no change in the hand value of the knitted fabric with the W/A-blended yarn caused by the change in the blending ratio before washing. After washing, however, the increase of acrylic's blending rate caused the bending property to decrease proportionally, while the friction coefficient of the surface property increased. Furthermore, the study showed that W/A 50/50 possesses the most superior tensile property and shearing property, which could attain the optimum blending ratio. Similar results in hand value were derived in all the samples. After washing, however, the increase in acrylic's blending rate caused a proportional decrease in KOSHI and an increase in FUKURAMI. In addition, W/A 50/50 gained the biggest NUMERI value, again corresponding to the optimum blending ratio. Similar results in total hand value were derived in all the samples before washing. After washing, though, all the total hand values decreased, and, as the wool fabric's blending rate increased, the total hand values proportionally decreased further.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.984-990
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• 2014

Polymers are the most commonly used di-electrics because of their reliability, availability, ease of fabrication and cost. The commercial and industrial demand for advanced polymeric materials which are capable of being used in harsh environment is need of the hour. The study of the effect of electron beam irradiation on polymeric materials is an area of rapidly increasing interest. This paper discusses the resultant beneficial effects of electron beam irradiation on the SiR-EPDM blend having 50:50 composition. The changes in mechanical and electrical properties of SiR-EPDM blend which are exposed to three different doses of electron beam radiation namely 5 Mrad, 15 Mrad and 25 Mrad are presented. The irradiated blends are analyzed for their electro-mechanical and physico chemical properties. The electrical changes induced by irradiation are investigated by arc resistance, surface resistivity and volume resistivity measurements as per ASTM standards. The mechanical changes are observed by the measurement of tensile strength and elongation at break. Physico chemical investigation has been done using the FTIR, in order to investigate the irradiation induced chemical changes.