Article
  • The Glass Transition Behavior of the Telechelic Polybutadiene and its Polyurethane
  • Park BY, Kim JK, Yeo JK
  • Telechelic 폴리부타디엔과 이들 폴리우레탄의 유리전이온도 거동
  • 박보영, 김정국, 여종기
Abstract
The telechelic polybutadiene is a random terpolymer of cis-1,4, trans-1.4. and 1,2 vinyl isomers. The equation xiv(In by Gibbs- DiMarzio for the glass transition temperature(Tg) of a copolymer in terms of the microstucture and the Tg''s of the three homopolymers were used to verify the glass tran.iition behaviors of this prepolymer. The Tf of the polyurethane based on polybutafiene was measured with dilatometry and differential scanning calorimetry. The Tg of the liquid prepolymer is 191°K by DSC at the heating rate of lO℃/min. and its calculated value is 185°K, respectively. The fractional free volume, fg, at the Tg is apporximately 0.025±0.003, and the differences between the expansion coefficients above and below Tg are 3.67×10-4K-1 and 4.44×10-4K-1 by dilatometry in these compounds. The "universal constants" C1g, C1g values from the Williams-Landel-Ferry equation were modified for the temperature range between Tg and Tg+100℃. The peaks of the tanδ were also shifted at different frequencies in dynamic tests, and the activation energy (ΔH) for the process was obtained from the log aT against the reciprocal of the absolute temperature.

텔리케릭 폴리부타디엔은 cis-1,4, tracts-1,4 와 vinyl-1,2의 이성체인 terpolymer이다. 이들 각각의 homopolymer와 공중합체에 관한 Gibbs-DiMarzio 개념의 유리전이온도(Tg)로부터 이 프리폴리머의 유리전이거동을 살펴보았다. 폰리우레탄의 T(g)는 팽창계기(dilatometer)와 시차 주사열량계(DSC)로 측정하였다. 액상 프리폴리머를 분당 10℃로 승온한 시차 열량계의 결과와 계산한 값의 Tg는 각각 191°K와 185°K이다. 이들 조성의 Tg에서 fg값은 약 0.025±0.003이며, 팽창계수 차이는 3.67×10-4K-1이다. Williams-Landel-Ferry식을 이용하여 Tg<(100+Tg)범위에서 상수 C1g, C2g 값을 유추하였다. 또 한 동적 실험에서 주파수 변화에 대한 tanδ peak의 기선이동점으로 log aT와 절대온도의 역함수 관계로 활성화 에너지(ΔH)를 구하였다.

  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2022 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 1987; 11(3): 225-231

    Published online Jun 25, 1987