Polyurethane‐crosslinked epoxy resins. I. Mechanical behavior

Abstract

Abstract Polyurethane (PU) prepolymers based on poly(butylene adipate) (PBA) and poly(oxytetramethylene) (PTMO) polyols were employed as a crosslinking agent to the diglycidyl ether of bisphenol A (DGEBA). Then the DGEBA was cured with a tertiary amine catalyst to form PU‐crosslinked DGEBA. The tensile strength of both the PU(PBA)‐crosslinked DGEBA and PU(PTMO)‐crosslinked DGEBA systems increased to a maximum value with increasing PU content in the system and then decreased with further increasing PU content. Izod impact property of these PU‐crosslinked DGEBA indicated that the PU(PBA)‐crosslinked DGEBA had much more significant improvement than the PU(PTMO)‐crosslinked DGEBA. On the contrary, the fracture energy (G 1 C value) of the resultant PU‐crosslinked DGEBA showed that the PU(PTMO)‐crosslinked DGEBA had much higher G 1 C values than the PU(PBA)‐crosslinked DGEBA.