Article
  • Molecular Weight and Polyelectrolyte Effect of Poly(amic acid) in Dilute Solution
  • Kim MJ, Ahn TK, Park JH, Choe S
  • 희석용액에서 폴리아믹산의 분자량과 고분자 전해질 효과
  • 김모준, 안태관, 박정환, 최순자
Abstract
The polyelectrolyte effect in dilute solution on the molecular weight of poly (amic acid) based on BTDA (3,3',4,4'-benzophenone tetracarboxylic dianhydride) with various diamines has been studied by means of GPC. The results from the molecular weight measurements showed that the polyelectrolyte effect is strong in highly diluted solution of the various poly(amic acid )s, while the effect was reduced by the addition of salt. The number and weight average molecular weights of the poly( amic acid) were consistent for the incorporation of 0.02 and 0.05 M of LiBr, however high concentrations of LiBr, which is 0.1 M or 0.2 M, perturbed the mo1ecular weight. Thereby the maximum concentration of the salt to reduce the polyelectrolyte effect is suggested 0.05 M. In addition, FT-IR spectroscopy and DSC were used for verification of the synthesized poly(amic acid) and fully imidized polyimide.

디안히드리드인 BTDA (3,3',4,4'-benzophenone tetracarboxylic dianhydride)를 기초로 하여 합성한 다양한 구조의 폴리아믹산 희석용액과 염의 첨가에 따른 폴리아믹산의 고분자 전해질 거동이 분자량 측정에 미치는 영향을 조사하였다. 이동상 용매로 dimethylacetamide (DMAc)를 이용하여 GPC (gel permeation chromatography) 칼럼에 통과되는 용출시간의 차이로 분자량을 측정하였으며, 이동상 용매에 각각 0.02, 0.05, 0.1, 0.2 M의 염 (LiBr)을 첨가함으로써 이동상에서의 염의 농도가 분자량에 미치는 영향을 살펴보았다. 다양한 폴리아믹산 회석용액으로부터 고분자 전해질 효과에 의한 과다한 분자량의 측정이 입증되었으며, 0.02∼0.05 M의 염이 첨가되었을 때 실제 분자량에 가까운, 20000∼30000 정도의 중량평균 분자량을 얻었다. 또한 제조한 폴리아믹산 분말의 이미드화 여부는 FT-IR 분광법 (Fourier transform infrared spectroscopy)을 이용하여 관찰하였으며, 충분히 열 경화시켜 시차열분석법 (differential scanning calorimetry)으로 유리전이온도를 측정하여 합성이 제대로 이루어졌는지 확인하였다.

Keywords: polyelectrolyte; poly(amic acid); GPC(SEC) analysis

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  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2023 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 1996; 20(5): 885-892

    Published online Sep 25, 1996