Available TPUs

Some principal suppliers of commercial TPU ranges are given in Table 9.6 and some typical property ranges in Table 9.7. From this data and a consideration of the chemical compositions of the polymer it is obvious that TPUs are very similar in general properties to the cast polyurethanes. 

TYPICAL PROPERTIES OF SOME COMMERCIALLY AVAILABLE TPUs  

Grade Chemical type 85 AK Caprolactone 65 AK Caprolactone 85 AK Not known MX Not known EY Not known SM Not known  

S4620 Poly- ester S8300 Poly- ether S4351 Polycapro- lactone 480A Not known 192A Not known 355D Not known 385 Not known J88 Not known PU 1478 Not known 

Hardness, shore Density (gcm ) Tensile strength (MPa) Modulus (MPa) 

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TPU is usually made from hydroxyl-terminated polyether or polyester diols, diisocyanates, and bifunctional chain extenders. Since the composition, the synthetic method, molecular weight, and its distribution are all changeable, there are numerous types of TPUs available, and their prices and properties vary significantly. 

Several commercial products of PVC/TPU blends are available. The BF Goodrich Chemical Group has a PVC/ TPU blend based on their Estane series TPUs. For example, their Estane 54620, a polyester-based TPU with a °ShA 85 hardness, shows excellent compatibility with flexible PVC. The blends are produced by mixing PVC, TPU, plasticizer, stabilizer, and lubricant in a twin-screw extruder. These polymeric blends show intermediate mechanical properties between PVC and TPU. 

Alzeta states that their TPUs can achieve 99.99% destruction with emissions of nitrogen oxides and carbon monoxide of <10 parts per million (ppm) corrected for 3% oxygen emissions. They also state the Alzeta systems prevent the formation of dioxins and furans, and are available with several different operating systems and capacities for different site requirements. 

The techniques available for processing TPUs are injection moulding, extrusion, calendering and solution fabrication. Usually speciality grades... 

In fact, thermoplastic polyurethanes (TPU), a subcategory of TPEs, were among the first to be made commercially available. In the United States, TPUs were marketed for the first time in the 1960s by Goodrich, Mobay, and Upjohn under the trade names Estane , Texin , and Pellethane , respectively. In 1972, DuPont commercialized thermoplastic poly(ether ester)s derived from... 

A number of investigators have characterized the morphology and properties of H12MDI based TPUs [7-11]. Because most of these studies used commercially available H12MDI (isomeric mixture), the resulting TPUs typically displayed less hard segment ordering and crystallinity than... 

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