• 제목/요약/키워드: elastomers

검색결과 1,665건 처리시간 0.027초

Preparation and Properties of Segmented Polyurethane Elastomers with Two Different Soft Segments

  • Lee, Tae-Jung;Huh, Jae-Ho;Kim, Han-Do
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 1998년도 봄 학술발표회 논문집
    • /
    • pp.1-4
    • /
    • 1998
  • Segmented Polyurethanes Elastomers are a class of polymers having interesting properties which arise from their unique phase-separated structures resulting from the thermodynamic incompatibility of the ingredients[1]. Segmented polyurethane Elastomer generally consists of a segment derived from a polymeric diol and a hard segment from a diisocyanate and a low molecular weight diol(chain extender).(omitted)

  • PDF

Relaxation Behavior of Thermo-Plastic Elastomers

  • 도문석;이한섭;서승원
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 1998년도 가을 학술발표회논문집
    • /
    • pp.203-206
    • /
    • 1998
  • 열가소성 탄성체(Thermoplastic elastomers)의 일종인 polyurethane은 상온보다 높은 유리전이온도(T$_{g}$)를 갖는 hard segment(HS)와 낮은 T$_{g}$를 갖는 soft segment(SS)간의 열역학적 불친화성으로 인해 미세 상분리 구조를 갖는다. SS는 낮은 T$_{g}$로 인해 상온에서 rubbery한 성격을 나타내며 HS는 높은 T$_{g}$로 인해 물리적 가교 역할과 충진제 역할을 한다. Polyurethane은 중합당시의 조성이나 중합방법에 따라 다양한 내부구조를 갖으며 이런 내부구조의 변화에 따른 물리적 성질의 변화 역시 다양하다. (중략)

  • PDF

Sythesis and Properties of Liquid Crystalline Polyurethane Elastomers

  • Lee, Tae-Jung;Lee, Dong-Jin;Kim, Han-Do
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 1998년도 가을 학술발표회논문집
    • /
    • pp.98-101
    • /
    • 1998
  • Segmented polyurethane elastomers are an important class of polymeric materials consisting of thermodynamically incompatible hard and soft segments. Due to the chemical structural difference between the hard and soft segments, a microphase separation occurs, consisting of crystalline hard domains and amorphous soft domains. (omitted)

  • PDF

폴리머 용액에서의 기포 형성 (Bubble Nucleation in Polymer Solutions)

  • 강성린;김기영;곽호영
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2003년도 추계학술대회
    • /
    • pp.1228-1233
    • /
    • 2003
  • The molecular cluster model for the homogeneous bubble nucleation was extended to predict the bubble nucleation events in elastomers, polymers and polymer solutions. For the bubble nucleation in elastomers and polymers, the strain energy overcome by a critical bubble was also considered. The calculation results for the number of bubbles nucleated are in good agreement with observed ones.

  • PDF

용액중합 SBR의 내림효과에 관한 연구 (A Study on the Effect of Mastication in Solution SBR)

  • 오정훈;윤동일
    • Elastomers and Composites
    • /
    • 제27권4호
    • /
    • pp.262-266
    • /
    • 1992
  • A number of tin-containing elastomers are produced commercially by Korea Kumho Petrochemical Co., Ltd. (KKPC) under the Kosyn Sol tradename. The effect of mastication of commercial and laboratory polymerized S-SBR has, been investigated using chemical mixer(ML-500), NMR, GPC and Mooney viscometer. Mastication of polymers containings coupling bonds is affected by the amount of stearic acid, the temperature of mixing and the time length of mixing.

  • PDF