Abstract: Recycling process of waste thermosetting polyurethane was proposed based on mechanical and physical methods, assuming the plastic had a three-dimensional reticular cross-linkage body structure. Using RNG k-ε dual equation turbulence model, a high speed flow field numerical simulation in the smashing recovery process was completed and optimal parameters of materials degradation process were obtained. The experiment showed speed and time factors had the greatest impact on the process. Finally, At last, the physical properties and morphology structure during the recycling was studied. ATR-FTIR infrared analysis proved that carbamate group may break at C-O bonding when the device speed exceeds 1500r/min and the experimental time exceeded 120 min. It meant that crosslinked structure was destroyed and the material resumed a thermoplastic behavior.

Key words: thermosetting polyurethane, degradation, recycling, grinding