Fluorinated anhydride-terminated imide oligomers toward high-performance epoxy thermosets enabled by hydroxyl elimination and low dielectric polarizability strategy

In this paper, for the first time, a novel fluorinated anhydride-terminated imide oligomer 6FDA-ODA was prepared with a facile and one-step route, and used as the multifunctional co-curing agent of methylhexahydrophthalic anhydride (MHHPA) for commercial bisphenol A epoxy resin (DGEBA). For the epoxy thermoset containing 30 phr of 6FDA-ODA, 6FDA-ODA-30 exhibited a high glass transition temperature ( T g ) of 151.6 ℃ and an initial degradation temperature of 382.5 ℃, and also showed a 211%, 134% and 11.8% increase in impact strength (20.5 kJ/m 2 vs. 6.6 kJ/m 2 ), char yield (in N 2 ) (15.2% vs. 6.5%) and tensile strength (71.3 MPa vs. 63.8 MPa), respectively, compared with the pure epoxy thermoset (6FDA-ODA-0). Moreover, 6FDA-ODA-30 possessed a low dielectric constant of 3.23 at 1 MHz and high water resistance (water absorption = 0.52%) due to the introduction of bulky trifluoromethyl (-CF 3 ) and imide moieties. This paper provides a facile design strategy and new opportunity for synthesizing anhydride-terminated imide oligomer, possessing high potential for the utilization in advanced matrix materials for microelectronic and aerospace industries.