**Thermoplastic Polyurethanes (TPU)** are technically thermoplastic elastomers consisting of linear segmented block copolymers composed of hard and soft segments. TPU is a block copolymer consisting of alternating sequences of hard and soft segments or domains formed by the reaction of di-isocyanates with short-chain diols (chain extenders) and di-isocyanates with long-chain diols. By varying the ratio, structure, and/or molecular weight of the reaction compounds, a wide variety of TPU can be produced, allowing chemists to fine-tune the polymer's structure to the desired final properties.