Study of new fluorine-containing epoxy resin for low dielectric constant

In this work, the novel fluorine-containing epoxy resin, 2-diglycidylether of benzotrifluoride (DGEBTF), was prepared and the chemical structure of DGEBTF was confirmed by FT-IR, 13C NMR and 19F NMR spectroscopy. Also, the properties of DGEBTF/diaminodiphenyl methane (DDM) and well-known diglycidylether of bisphenol A (DGEBA)/DDM systems were investigated. As a result, the dielectric constant values of DGEBTF/DDM system were 15% lower than those of DGEBA/DDM system. The critical stress intensity factor and impact strength of DGEBTF/DDM and DGEBA/DDM systems were 5.63 MPa m1/2, 50 kN/m2 and 3.53 MPa m1/2, 26 kN/m2, respectively. The introduction of trifluoromethyl (CF3) group into the chain of the epoxy resin resulted in improving the dielectric and mechanical properties and enormously lowered the Tg (105 °C) of the studied DGEBTF/DDM. It comes from the internal network change of cured resin.