Healable adhesive paste development for thick adhesive joints

A new adhesive formulation is developed, enabling assisted self-healing for wind turbine rotor blade (WTRB) applications. The properties of this epoxy based formulation are compared to those of a state-of-the-art toughened epoxy adhesive (Sikapower (R)-830). An optimal content of 20 wt% poly(epsilon-caprolactone) (PCL) microparticles and 4 wt% fumed silica (NS) in a baseline epoxy fulfilled most requirements, such as sufficient rheological yield stress, adequate mechanical properties, glass transition temperature (Tg) higher than the operation temperature range and good adhesion, although the elastic modulus remained about 85% of the desired value. In addition, 60 % healing efficiency was achieved in fractured samples after moderate heating. This approach provides new perspectives to control damage in thick bonded joints.