Thermoplastic polyurethane is a linear segmented copolymer whose hard segments of diisocyanate and chain extender are joined to soft polyol segments by urethane linkages. The two segments separate into hard domains dispersed in a soft matrix, and the resulting physical crosslinks give elasticity without covalent network bonds [1]. Because the hard domains can be melted, the material can be processed by extrusion and injection molding and can be reprocessed, unlike a crosslinked polyurethane [2]. The hard-segment content sets the modulus and the softening temperature, while the polyol type sets the low-temperature flexibility and the hydrolysis resistance [3]. Polyester-based grades are stronger but hydrolyse more readily than polyether-based grades, so the choice is dictated by the service environment [4]. Bio-based polyols and non-isocyanate routes are being developed, though their property profiles do not yet match the conventional grades [5].
- segmented copolymer
- hard segment
- soft segment
- polyol
- phase separation
- chain extender
- reprocessing
References
- Osman, A.F.; Edwards, G.A.; Schiller, T.L.; Andriani, Y.; Jack, K.S.; Morrow, I.C.; Halley, P.J.; Martin, D.J.; Structure–Property Relationships in Biomedical Thermoplastic Polyurethane Nanocomposites. Macromolecules 2012, 45, 198-210, 10.1021/ma202189e.
- Alshammari, F.H.; Structure–property correlations, optical behavior, and dielectric relaxation dynamics in V2O5/thermoplastic polyurethane nanocomposites for flexible electronic applications. Ceramics International 2026, 52, 286-297, 10.1016/j.ceramint.2025.11.317.
- Brăileanu, P.I.; Mocanu, M.T.; Dobrescu, T.G.; Dobrotă, D.; Pascu, N.E.; Structure—Property—Performance Relationships in Thermoplastic Polyurethane: Influence of Infill Density and Surface Texture. Polymers 2025, 17, 2716, 10.3390/polym17192716.
- Jung, I.; Lee, S.; Electro-mechanical Property of 3D Printed Cubic Structure Using Carbon Materials/Thermoplastic Polyurethane Filament with Various Infill Patterns. Fibers and Polymers 2025, 26, 1717-1728, 10.1007/s12221-025-00901-8.
- Smorawska, J.; Włoch, M.; Głowińska, E.; Structure–Property Relationship and Multiple Processing Studies of Novel Bio-Based Thermoplastic Polyurethane Elastomers. Materials 2023, 16, 6246, 10.3390/ma16186246.