Soft thermoplastic polyurethane elastomers and process for their preparation

The present invention discloses a thermoplastic polyurethane comprising substantially no plasticizers and having a Shore A hardness of 60 or less, which is prepared by a one-step polymerization of i) linear polyol, ii) organic diisocyanate and iii) glycol chain extender mainly comprising ethylene glycol and/or 1,3-propanediol; wherein the linear polyol (i) has a number average molecular weight within the range of from 1.5 x 103 g/mol to 5.0 x 103 g/mol. The thermoplastic polyurethane of the present invention can be easily produced by conventional production methods, and the thermoplastic polyurethane thus produced can be molded to articles in practicable processing cycles. Moreover, the thermoplastic polyurethane articles have low shrinkage, have good low-temperature properties and good mechanical properties, and do not harden substantially at low temperature.