Design of castor oil‐based polyurethane thermal conductive structural adhesive for new energy batteries

A thermal conductive structural adhesive (TCSA) plays a crucial role in battery performance and safety. TCSA made of polyurethane (PU) has not only a good thermal conductivity but also good mechanical strength and substrate bonding strength. However, it has to be cost‐effective and easy to be prepared. This work aims to synthesize a series of castor oil‐based PU TCSAs with different amounts of thermal conductive powder using commercially available castor oil polyols, isocyanates, Al 2 O 3 , and additives. The shear strength of the TCSA containing 88% thermally conductivity powder reached 5.6 MPa, which was similar to that without the thermal conductivity fillers, but its toughness significantly decreased. Its thermal conductivity was as high as 1.8 W/mK, and it was thermally stable below 270°C.