Closed‐loop recycling of thermoset composites from electric motor assembly process into flexible polyurethane foams

Abstract Polyurethane foams (PU) are used in many automotive applications due to their durability and sound absorption properties. This paper examines the effects of reusing predominantly silica‐filled thermoset composites as a reinforcing agent when ground to a particle size less than 106 μm (0%, 2.5%, 5%, 7.5% by wt%) on mechanical, physical, thermal, and sound absorption properties of PU foam. Young's modulus improved by 27%, and tensile strength increased by 18% with 7.5% reinforcement. Compression stress improved at 25%, 50%, and 65% strain by 37%, 41%, and 44%, respectively, with the 7.5% filler. Compression modulus increased by 66% with 7.5% filler. The addition of the filler did not impact tensile extension or tear resistance. TGA showed increased thermal stability, and the sound absorption coefficient increased over a spectrum of frequencies. This research demonstrates a promising recycling opportunity for thermoset materials and how Ford Motor Company can create a closed‐loop recycling process from an assembly aid material into another vehicle application.