Mixed Polyol Product Families in Thermoplastic Polvurethane

摘要

The Dow Chemical Company has introduced new PELLETHANE~* Thermoplastic Polyurethane Elastomers (TPUs) incorporating dual polyol technology. Two new product families, the 2101 and 2104 series, have been developed. Both product families utilize combinations of polyols as the soft segment. These product families offer targeted functional performance in market segments where a lower cost option is desired versus conventional TPU resins. The 2101 series uses dual ether-based polyols and show general ether-type TPU properties. Some physical and chemical resistance properties are slightly inferior to straight polytetramethylene ether glycol (PTMEG) type TPUs at equivalent hardness but more than adequate for many market niches. They exhibit superior hydrolytic stability versus both polycaprolactone and polyadipate polyester based TPU. PELLETHANE 2101-85A has been demonstrated to be an excellent injection molding resin. Molding cycle time reductions have been demonstrated compared to standard PTMEG (polytetramethylene glycol) based ether TPUs of similar hardness. The 2104 series is manufactured using a combination of ester and ether polyols to form the soft segment. These products offer performance between that of conventional polyester and ether based TPU resins. The chemical resistance of these resins is comparable to conventional polyadipate and polycaprolactone polyester based TPU in select chemical reagents. In others they take on more of an ether-based TPU characteristic. For example, the hydrolytic stability is improved above ester based TPU, although not quite comparable to that of polytetramethylene ether glycol (PTMEG) ether based TPUs. Injection molding cycle time advantages have also been seen with PELLETHANE 2104-45D compared to standard polyester based TPUs of similar hardness. Both product families are manufactured using Dow's reactive extrusion technology. The technology is very flexible and new grades are planned as market opportunities are identified.