The synthesis methods of TPU can be divided into two categories according to the presence or absence of solvents: solvent-free bulk polymerization and solvent-based solution polymerization. Bulk polymerization can be further divided into one-step polymerization and prepolymer polymerization according to the reaction steps. One-step polymerization involves simultaneously mixing oligomeric diols, diisocyanates, and chain extenders. While simple and convenient, one-step polymerization is difficult to eliminate the heat of reaction and is prone to side reactions. A polyester-type thermoplastic polyurethane elastomer was synthesized using a one-step method. First, the prescribed amounts of polyester polyol, chain extender, and butanediol were weighed in a reactor and heated to 120°C for vacuum dehydration. The preheated mixture was then rapidly added and stirred until homogeneous. The mixture was poured into a preheated container and vacuum-dried at 120°C, then cooled to 100°C to obtain a light yellow, semi-transparent polyurethane product. This product was then pressed into test pieces on a flatbed press. The prepared TPU exhibited high mechanical and damping properties.
