Toughening of Epoxy/Ionic Liquid Networks with Thermoplastics Based on Poly(2,6-dimethyl-1,4-phenylene ether) (PPE)
文摘
This work deals with the use of two types of poly(2,6-dimethyl-1,4-phenylene ether) (PPE) having different molar masses as toughening agents of epoxy/ionic liquid networks where phosphonium ionic liquids (ILs) combined with phosphinate and phosphate counteranions were used as curing agents of the epoxy prepolymer. The effect of the chemical nature of the anions on the morphology as well as the final properties of PPE-modified epoxy networks was investigated. For the same amount of PPE thermoplastic (10 p.h.r.), a morphology characterized by the presence of PPE particles as dispersed phase was observed in epoxy/amine networks whereas cocontinuous or phase-inverted morphologies were obtained for epoxy/IL networks. As a consequence, compared to PPE-modified epoxy/amine networks, a pronounced hydrophobic character and an excellent thermal stability (i.e., higher than >400 °C) were observed for PPE-modified epoxy/IL networks. In addition, the IL-thermoplastic combination led to significant increases in the mechanical performances of the resulting epoxy networks, especially in the stress intensity factor, KIc (+150% for IL-TMP and +200% for IL-DEP).