PVC/TPU polymeric blends

Although relatively new, PVC/TPU polymeric blends have already found substantial applications in various fields. This is evident by the numerous patents applied for in this area. 

PVC has been widely used in every aspect of life. Its production has been refined and its quality is relatively stable. Unlike TPU, PVCs used in blending with TPU are almost exclusively from commercial sources. Most of them are made by suspension polymerization. 

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. 

These results showed that TPU, represented here by 566TPU, has the best overall results in modifying PVC among those tested. It has good compatibility with PVC, and the resulting polymeric blends have good mechanical properties suitable for various processing methods. 

Initially, two-component, PVC/TPU blends were proposed [B. F. Goodrich Co., 1960], but soon, PVC/TPU blends with a modifier, e.g., ABS [Waugaman et al., 1963] NBR or PA [Kepes, 1959] were disclosed. Blending was also carried out by mixing PVC with polyols and isocyanates then polymerizing these two [Dainichiseika Color Chemicals, 1983]. Commercial PVC/TPU (with NBR) are represented by Duralex . The materials are usually formulated for extrusion, e.g., for wire and cable insulation, hoses and packaging. 

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