The present invention discloses a high-crosslinking-degree, low-hardness, high-temperature-resistant and low-compression-set thermoplastic polyurethane (TPU) material, a preparation method thereof and application thereof as a crosslinking agent in TPU production. The present invention adopts an upper and lower two-stage twin-screw extruder. A melt with an R value less than 1 obtained by reactive extrusion of 10–70 parts by mass of macromolecular aliphatic diol, 10–70 parts by mass of macromolecular aromatic diol, 10–40 parts by mass of diisocyanate and 2–20 parts by mass of small-molecule diol chain extender through the upper-stage twin-screw extruder, is reacted and crosslinked with 1–15 parts by mass of 2,4-toluene diisocyanate dimer in the lower-stage twin-screw extruder at 90–150°C, extruded and cooled to obtain the high-crosslinking-degree, low-hardness, high-temperature-resistant and low-compression-set TPU material. Based on 100% of the total mass of the macromolecular aliphatic diol and the macromolecular aromatic diol, the mass percentage of the macromolecular aliphatic diol is 50%–80%.
Country Code: CN
Application Number: CN202410208959.8
