• 제목/요약/키워드: Poly vinyl alcohol fiber

검색결과 111건 처리시간 0.02초

일욕 현탁중합과 비누화에 의한 고분자량 폴리비닐알코올의 고수율 제조 및 그의 특성해석 (Synthesis of High Molecular Weight Poly(vinyl Alcohol) with High Yield by 1 Batch Suspension Polymerization and Saponification and Its Characterization)

  • Lee, Hee-Won;Lyoo, Won-Seok
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 2001년도 가을 학술발표회 논문집
    • /
    • pp.187-190
    • /
    • 2001
  • The poly(vinyl alcohol) (PVA) fiber is recognized as the best candidate because of its good machanical properties together with excellent resistance to alkalis[1-5]. PVA cannot be prepared by the direct polymerization due to tautomerism of vinyl alcohol monomer. Thus PVA is obtained by the saponification of poly(vinyl ester) like poly(vinyl acetate) (PVAc). (omitted)

  • PDF

Poly(vinyl alcohol) block의 신디오탁틱이 Poly(vinyl alcohol-b-styrene)의 micelle형성에 미치는 영향 (Influence of the Syndiotacticity of Poly(vinyl alcohol) block on the formation of micelles for Poly(vinyl alcohol-b-styrene))

  • 이광화;조창기
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 2003년도 봄 학술발표회 논문집
    • /
    • pp.291-292
    • /
    • 2003
  • Amphiphilic block copolymer는 self-assembly특성을 가지고 있기 때문에 선택된 용매 속에서 nanoscale-domain 즉 micelle을 형성할 수 있다. 이러한 특성은 기타 불용성 물질을 가용화하고 colloidal particle을 안정화시키거나 micro-emulsion을 형성할 수 있어 pharmaceutics, drug delivery system등 영역, 그리고 emulsion stabilizer, thickener, dispersion agent등으로 사용될 수 있다. (중략)

  • PDF

Synthesis and Characterization of Poly(vinyl alcohol-b-styrene) via Atom Transfer Radical Polymerization and Saponification

  • Li, Guang-Hua;Cho, Chang-Gi
    • Macromolecular Research
    • /
    • 제10권6호
    • /
    • pp.339-344
    • /
    • 2002
  • Poly(vinyl alcohol-b-styrene) (poly(VA-b-St)) diblock copolymer containing high syndiotactic poly (vinyl alcohol) (PVA) was synthesized by the saponification of poly(vinyl pivalate-b-styrene) (poly(VPi-b-St)). For the block copolymer, poly(vinyl pivalate) (PVPi) with trichloromethyl end group was obtained via telomerization of vinyl pivalate with carbon tetrachloride as a telogen and 2,2-azobisisobutyronitrile (AIBN) as an initiator. Then resulting poly(vinyl pivalate) with trichloromethyl end group was used as an effient macroinitiator for the synthesis of poly(VPi-b-St) using atom transfer radical polymerization (ATRP) in the presence of CuCl/2,2'-bipyridine at 130 $^{\circ}C$. The poly(vinyl pivalate) macroinitiator, poly(VPi-b-St), poly(VA-b-St) were characterized by GPC, FT-IR and $^1$H-NMR. And the analysis showed that integrity of the block copolymer was maintained during saponification reaction.

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

  • 임상규;손태원
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 1996년도 춘계학술발표회 논문집
    • /
    • pp.64-68
    • /
    • 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.

  • PDF

Critical Syndiotacticity Required for In-Situ Fibrillation of Poly(vinyl Alcohol) during Saponification of Poly(vinyl Ester)

  • Lyoo, Won-Seok;John Blackwell
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 1998년도 봄 학술발표회 논문집
    • /
    • pp.130-134
    • /
    • 1998
  • The physical properties of poly(vinyl alcohol) (PVA) are highly dependent on the degree of syndiotacticity, which is determined primarily by the choice of the vinyl ester monomer precursor. Efforts to produce more syndiotactic PVAs, as well to increase the molecular weight, have centered on the polymerization of vinyl trifluoroacetate,$^1$ vinyl trichloroacetate,$^2$ and vinyl pivalate (VPi).(omitted)

  • PDF

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
    • /
    • 한국섬유공학회 2001년도 가을 학술발표회 논문집
    • /
    • pp.368-370
    • /
    • 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)

  • PDF

Molecular Modeling for the Crystal Structure of Stereoregular Poly(vinyl Alcohol) (I) - New Crystal Dimension of Syndiotactic Poly(vinyl Alcohol) -

  • Lyoo, Won-Seok;Sergei Chvalun;John Blackwell
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 1998년도 봄 학술발표회 논문집
    • /
    • pp.135-139
    • /
    • 1998
  • Poly(vinyl acetate) (PVAc) from which atactic poly(vinyl alcohol) (PVA) is derived, is always noncrystalline. This was attributed to the irregular steric arrangement of the acetyl groups in PVAc. However, the X-ray diffraction patterns of atactic PVA, a derivative of PVAc, were found to show distinct crystallinity, and to give an identity period of 2,52 ${\AA}$ along the fiber axis, despite the expectation of an irregular arrangement of the hydroxyl groups in atactic PVA, in the same manner as that of the acetyl groups in PVAc.(omitted)

  • PDF

Critical Molecular Parameters for Fibrillation of Poly(vinyl alcohol) during Saponification

  • Lyoo, Won-Seok
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
    • /
    • pp.61-62
    • /
    • 2003
  • To identify the effect of critical molecular parameters of poly(vinyl alcohol) (PVA) such as syndiotacticity, degree of saponification, and molecular weight on the change of morphology, we prepared various PVAs. Also, the structures of these PVA were investigated.

  • PDF