• 제목/요약/키워드: vinyl

검색결과 2,424건 처리시간 0.113초

Water Content Reduction in Poly(vinyl butylal) during Magic Angle Spinning

  • Han, Oc Hee;Jeong, SoonYong
    • 한국자기공명학회논문지
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    • 제7권2호
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    • pp.68-73
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    • 2003
  • Proton magic angle spinning spectra and thermogravimetric analysis data of poly(vinyl butylal) with water in it indicate water contents in the poly(vinyl butylal) samples were reduced during magic angle spinning. Our observation implies that the centrifugal force on the samples due to magic angle spinning cannot be neglected, especially on inhomogeneous and soft samples like poly(vinyl butylal) we tested in this work.

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폴리비닐알코올 마이크로피브릴 섬유의 염색 -마이크로피브릴 섬유의 표면적 평가- (Dyeing of Microfibrillar Poly(vinyl Alcohol) Fiber - Evaluation of Surface Area of Microfibrillar Fiber-)

  • 김한도;김재필;김삼수;류원석
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2001년도 가을 학술발표회 논문집
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    • pp.368-370
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    • 2001
  • 폴리비닐알코올(poly(vinyl alcohol) (PVA))은 구조적인 단량체인 비닐알코올의 호변 이성질화 때문에 직접 중합에 의해서는 얻을 수 없으며, 아세트산 비닐 (vinyl acetate (VAc))이나 피발산 비닐 (vinyl pivalate (VPi))같은 비닐에스테르 계열 단량체를 사용하여 중합과 비누화 반응을 거쳐 제조되고 비누화 반응에서 모든 측쇄기가 효과적으로 제거되는 히드록시기 함유 선형 결정성 고분자이다[1-4]. (중략)

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폴리프로필렌의 친수화 개질 -Polypropylene-poly(vinyl alcohol-co-ethylene) 블렌드의 특성-

  • 임상규;손태원
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 1996년도 춘계학술발표회 논문집
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    • pp.64-68
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    • 1996
  • PP-EVOH(poly(vinyl alchol-co-ethylene)) blends were prepared by the mixing of polypropylene and poly(vinyl alcohol-co-ethylene) containing 38mol% of ethylene units (EVOH38) at melt state above PP melting temperature. The materials were characterized by using dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and contact angle measurement to detemine the glass transition, meltin, decomposition temperatures, and wettability respectively. From the results, PP-EVOH(poly(vinyl alcohol-co-ethylene)) blends exgibits partial miscibility.

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농촌시설물 유지관리 지침서 개발 - 비닐하우스와 유리온실을 중심으로 - (A Maintenance Guide Development for Agricultural Facilities - Focused in vinyl greenhouse and Glasshouse -)

  • 정재혁;신한우;김태희;김광희
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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    • pp.213-214
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    • 2011
  • Vinyl greenhouse and glass house account for the greatest parts in the agricultural facilities. However, these cause the serious economic loss lacking of the maintenance guide in a lot of natural disasters. This study developed the maintenance guide concerning the vinyl greenhouse and glass house by collecting materials with literature review and improving problems with existing guides.

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실리콘 폴리머의 내전압 및 절연특성에 관한 연구 (A Study on Dielectric Strength and Insulation Properly of PDMS)

  • 지원영
    • 한국전기전자재료학회논문지
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    • 제14권11호
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    • pp.941-946
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    • 2001
  • The fundamental study on HTV silicone for insulation material has been performed. In order to estimate the chemical behavior of siloxane under high voltage, H-NMR, GPC and vinyl contents measurement were used. As an experimental results, after high voltage stress, the molecular weight of siloxane are increased, the vinyl contents of siloxane are decreased. The dielectric strength of vinyl group containing siloxane was lower than only methyl containing siloxane.

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Reactions of Metal Catalysts with Polar Vinyl Monomers

  • Jordan Richard F.
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.153-154
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    • 2006
  • The development of metal catalysts that can polymerize or copolymerize "polar" $Ch_2=CHX$ monomers by insertion mechanisms would significantly expand the scope of metal-catalyzed polymerization and enable the synthesis of new materials with enhanced properties. We have studied the reactions of single-site olefin polymerization catalysts with vinyl chloride, acrylonitrile, and vinyl ethers, in order to probe monomer coordination trends, insertion rates and regioselectivity, and the structures and reactivity of metal alkyls that contain functional groups on the alpha and beta positions of the alkyl chain. These studies provide insights to the key issues that underlie the "polar monomer" problem. Copolymerization of olefins and selected vinyl ethers has been achieved.

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서로 다른 봉지재료가 포도 품질 및 숙기판단 노력에 미치는 영향 (The effect of different bag materials on grape quality and endeavor of maturation period determination)

  • 남상영;강한철;김태수
    • 한국자원식물학회지
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    • 제13권2호
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    • pp.111-117
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    • 2000
  • 포도 품질을 높일 수 있고, 숙기 판단 노력을 절감할 수 있는 봉지 재료를 선발하고자 1997년부터 1999년까지 3년간에 걸쳐 충청북도 농업기술원 옥천포도시험장에서 시험한 결과를 요약하면 다음과 같다. 봉지내의 광 투과율은 종이 봉지에 비하여 부직포 및 무적비닐 이용 봉지에서 11∼65%가 높았으나, 무적비닐 천공 상면 50% 흰색 페인팅 봉지는 25% 낮았다. 과립중은 종이봉지에 비하여 부직포와 무적비닐이용 봉지에서 무거웠으며, 무적비닐 천공 상면 50% 흰색 페인팅 봉지는 열과, 탈립 및 부패과가 심하여 조사가 불가능하였다. 숙기는 종이봉지에 비하여 부직포와 무적비닐 이용 봉지에서 1∼4일 빨랐다. 당도는 부직포와 무적비닐 이용 봉지에서 높은 경향이었으나, 산도는 상반된 경향이었다. 착색정도는 종이 봉지에 비하여 부직포와 무적비닐 이용 봉지에서 빨랐으며, 이들 봉지간에는 착색 정도는 맥반석 혼합 부직포와 무적비닐+부직포 봉지에서 빨랐으나, 적숙기로 가까워질수록 부직 포봉지에서 빨랐다. 비정상 과립율은 종이와 부직포 봉지는 5.4∼7.0%로 낮았으나, 무적비닐 이용 봉지는 16.6∼100%로 높았다. 외관상품질은 부직포와 맥반석 혼합 부직포에서 지수 9.0으로 가장 좋았으나, 무적비닐 천공 상면 50% 흰색 페인팅 봉지는 지수 1.0으로 가장 불량하였다. 숙기 판단 소요시간은 종이(17.4시간/10a)에 비하여 부직포와 무적비닐 이용 봉지에서 74∼93% 절감되었다.

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비닐 피복과 재식밀도가 목화의 생육 및 수량에 미치는 영향 (Influences of PE Film Mulching and Planting Density on Growth and Yield of Cotton)

  • 박희진;김상곤;정동희;박홍재;권병선
    • 한국작물학회지
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    • 제40권1호
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    • pp.39-43
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    • 1995
  • 남부지방의 목화 재배체계 및 안전다수확을 위한 지초자과를 얻고자 Vinyl 피복과 무피복 재배아래서 재식밀도 차이에 따른 생육, 수량 및 면모의 발생등을 검토하였던 바 다음과 같은 결과를 얻었다. 1. 경장, 결과피수, 삭수$m^2$당 삭수 등의 모든 형질이 Vinyl피복구에서 우수하였으며$m^2$당 삭수는 Vinyl피복구에서나 무피복구에서나 70${\times}$10cm재식에서 가장 우수하였다. 2. 실면수량과 1삭실면중 역시 Vinyl피복구에서 높았으며 실면수량은 Vinyl피복구와 무피복구 모두 70${\times}$10cm재식에서 가장 우수하였다. 3. 섬유장, 섬유비율 모두 Vinyl피복의 결과가 인정되었으며 섬유장은 주문거리가 넓을수록 길었다.

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Vinyloligosilsesquioxane 함유 의치상용 아크릴릭 레진의 마모 저항성 (ABRASION RESISTANCE OF DENTURE BASE RESIN INCLUDING VINYLOLIGOSILSESQUIOXANE)

  • 박란;심준성;한동후
    • 대한치과보철학회지
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    • 제41권5호
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    • pp.626-639
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    • 2003
  • Statement of problem : Recently, in attempts to reinforce the acrylic resin and to reduce the polymerization shrinkage, it has been reported that adding vinyloligo-silsesquioxane (vinyl-POSS) to PMMA significantly compensates for polymerization shrinkage and somewhat increases the fracture resistance. Purpose : There haven't been any studies on abrasion that can affect the adaptation of the denture in long-term use. In this study abrasion resistance was compared between acrylic resin with vinyl-POSS and commercialized acrylic resin for denture base. In addition, the difference in abrasion resistance according to molding methods was compared. Material and method : Using PaladentR 20 including vinyl-POSS. PaladentR 20, Lucitone 199R, SR IvocapR, denture bases were fabricated using compression molding technique and continuous-pressure injection technique. Surface hardness and abrasion were measured for each group, and the worn surfaces were observed under a scanning electron microscope. Results : 1. When surface hardness was measured for each material and molding technique, there was no statistically significant difference among the materials. (p<0.05) 2. When same denture base material and molding technique were used, the abrasion due to toothpaste solution was 5 times as severe as the abrasion due to soap solution. 3, When toothpaste solution was used, the abrasion decreased in the order of PaladentR20, PaladentR 20 including vinyl-POSS, SR IvocapR, and Lucitone 199R. However statistically significant difference was seen only among PaladentR 20, SR IvocapR, and Lucitone 199R. (p<0.05). 4. When soap solution was used, the abrasion was more severe in PaladentR 20 and including vinyl-POSS PaladentR 20 groups than in SR IvocapR and Lucitone 199R groups. (p<0.05). Conclusion : Addition of vinyl-POSS doesn't improve the abrasion resistance, and the abrasion resistance was similar to those of existing materials. Additional studies under different conditions are needed. For clinical application of vinyl-POSS, further investigations with different requirements and conditions are necessary.

Effects of soil covering materials on the overwintering and the growth of Cynanchum wilfordii Hemsley

  • Youn, Cheol Ku;Kim, Ki Hyun;Kim, In Jae;Lee, Hee Do;Hong, Seong Taek;Hong, Eui Yon;Kim, Young Kuk;Jang, Jae Gi
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.251-251
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    • 2017
  • This study was performed to select the soil covering materials for winter safety of Cynanchum wilfordii Hemsley and to investigate the effect on the growth after overwinter. Soil covering materials such as vinyl, rice straw, lagging cover, vinyl+lagging cover, and non-covering were investigated how effect on overwintering rate, growth and yield of Cynanchum wilfordii Hemsley. In changes of soil temperature according to the soil covering materials, non-covering treatment was recorded the highest to $26.7^{\circ}C$, and lagging cover and rice straw showed little change of soil temperature with 9.2 and $9.3^{\circ}C$, respectively. Regrowth rates of early growth after overwinter were lowered in the order as rice straw > vinly+lagging cover > lagging cover > vinyl > non-covering. From the above-ground growth by soil covering materials, vine length showed similar growth in all treatments except vinyl covering and stem diameter exhibited the thicker pattern in vinyl and lagging cover, and there was no significant difference among treatments in number of branch. Flowering period is recorded July 30 in all treatments and ripening period is October 16. Yield of seed production is showed the best in vinyl+lagging cover with $25g/m^2$. Root weight and root length for subterranean growth showed no significant differences among all treatments. Yield is produced the highest in vinyl+lagging cover with 433kg/10a and the next to lagging cover with 431kg/10a. In comparison with incomes, lagging cover earned to 9,882 thousand won/10a, showed the effect on income enlargement to 21%, compare to that of the non-covering.

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