| 초록 |
A new type of epoxy resin (2,4-diglycidylether of benzotrifluoride), which contained fluorine groups in the main chain, was synthesized. The synthesized resins were characterized by IR and 13C-NMR spectroscopy. New epoxy resins were cured by triethylene tetramine (TETA). And, the effect of fluorine group to the epoxy resins on the cure behavior, thermal, and mechanical properties was investigated. The cure activation energy (Ea) of the epoxy resins was evaluated from the differential scanning calorimetry (DSC) and thermal stability of the cured specimen was monitored by thermogravimetric analysis (TGA). Also, the critical stress intensity factor (KIC) was measured by UTM. As experimental results, it was obtained that epoxy resins were cured at room temperature and the cure activation energy (Ea) was calculated at 61 kJ/mol. The cured epoxy resins showed a higher fracture toughness. However, thermal properties the resin studied were lower than those of commercial DGEBA resins. This was due to the decrease of bonding strength for crosslinked C-C bond, resulted from the formation of C-F bond.
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