Article
  • Thermal and Mechanical Properties in an Epoxy/Anhydride System: Effect of Mixing Ratio and Accelerator
  • Kim DS, Lee JK, Choi EJ
  • 에폭시/산무수물계의 열적. 기계적 성질 : 혼합비와 경화촉진제의 효과
  • 김득수, 이종근, 최이준
Abstract
Cure behavior and thermal/mechanical properties of an epoxy/anhydride system with two different accelerators, 1-cyanoethyl-2-ethy-4-methyl imidazole(2E4MZ-CN) and N,N-dimethyl benzyl amine (BDMA), were examined for samples with various mixing ratios of anhydrie to epoxy (γ=0.3, 0.5, 0.7, 0.9, 1.1). Differential scanning calorimeter(DSC) experiments for uncured samples show that cure process is greatly influenced by bothe γ and accelerator. Samples precured at 105 ℃ for 10 h and postcured at 160 ℃ for 5 h after the precure were also investigated by differential scanning calorimeter and dynamic mechanical analyzer(DMA). For 2E4MZ-CN, the glass transition temperature(Tg) of the precured samples does not change much with respect to γ anging from 128.7 ℃ to 139.1 ℃, while that of the postcured increases gradually with decreasign γ from 130.2 ℃ (γ=1.1) to 158.3 ℃(γ=0.3). However, for BDMA, the maxima in Tg vs. γ for the cured and the postcured occur at a stoichiomeric mixture (γ=0.9): Tg=137.4 ℃ and 147.9 ℃, respectively. In this study, the average molecular weight between crosslinks(Mc), modulus at a glassy state(Eg''), and secondary transition were also examined for various mixing ratios with different accelerators.

에폭시와 산무수물계의 혼합비 (γ=산무수물/에폭시)를 0.3, 0.5, 0.7, 0.9, 1.1로 변화시켜 두 종류의 경화촉진제 1-cyanoethyl-2-ethyl-4-methyl imidazole (2E4MZ-추)과 N,N-dimethyl benzyl amine (BDMA)을 각각 첨가한 미경화물의 경화거동과 경화물의 열적. 기계적 성질을 조사하였다. 미경화물ㄹ의 경화거동을 시차주사 열량분석기 (differential scanning calorimeter, DSC)로 조사해 본 결과 경화반응기구가 혼합비와 경화촉진제에 크게 영향을 받는다는 것을 알 수 있었다. 그리고 105 ℃에서 10시간 경화시킨 것 (선견화물)과 이것을 다시 160 ℃에서 5시간 경화시킨 것 (후경화물)의 성질을 시차주사 열량분석기와 동역학측정기 (dynamic mechanical anasition temperature, Tg)는 2E4MZ-CN의 경우 γ이 변화할 때 128.7-139.1 ℃의 범위에서 큰 변화를 보이지 않지만, 후경화 처리를 하면 γ=1.1에서 Tg가 130.2 ℃이고 γ값이 감소함에 따라 점차 증가하여 γ=0.3에서는 Tg가 158.3 ℃로 최대가 되었다. 반면에 BDMA의 경우는 선경화물과 후경화물의 Tg가 화학양론비인 γ=0.9애소 137.4 ℃와 147.9 ℃로 각각 최대치를 나타내었다. 본 연구에서는 선경화물과 후경화물의 가교점간의 평균분자량 (Mc), 유리상에서의 탄성율 (E`g), 그리고 이차전이 등도 조사하였다.

Keywords: epoxy; anhydride; accelerator; mixing ratio

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  • 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

  • 1999; 23(4): 569-579

    Published online Jul 25, 1999