Characterization of imidazole-cured epoxy–phenol resins

Authors

  • M. S. Heise,

    1. Department of Chemical Engineering and Materials Science, Syracuse University, Syracuse, New York 13244
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    • Hercules Incorporated, Research Center, Wilmington, DE 19894.

  • G. C. Martin,

    Corresponding author
    1. Department of Chemical Engineering and Materials Science, Syracuse University, Syracuse, New York 13244
    • Department of Chemical Engineering and Materials Science, Syracuse University, Syracuse, New York 13244
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  • J. T. Gotro

    1. IBM Corporation, Systems Technology Division, Endicott, New York 13760
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Abstract

The physical and chemical properties of the diglycidyl ether of bisphenol A (DGEBA) cured with different concentrations of bisphenol A (BPA) and 2-ethyl-4-methylimidazole (EMI-24) were examined using Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical and dielectric analyses, and solvent extraction studies. The effects of the phenol-epoxide and the secondary hydroxyl (R-OH)-epoxide reactions on the network formation process were analyzed using a recursive modeling technique to obtain expressions for the weight-averaged molecular weight, the weight fraction solubles, and the gel point as a function of the extent of cure and the epoxide-phenol reactant ratio. The sol fraction and the gel point predictions from recursive modeling studies of the network formation process agreed with the results obtained from the extraction studies. The results from the network modeling studies were also related to the thermal and rheological properties of the resin during cure.

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