Application of Diene-Based Thermoplastic Polyurethanes in Rubber Compounding
|Date Published||January 1, 2006|
New grades of thermoplastic polyurethane (TPU) product based on difunctional hydroxyl-terminated polybutadiene resins offer unique application possibilities in traditional rubber compounding. The TPU products are formed from linear prepolymers derived from Krasol® LBH polybutadiene diols and diisocyanates. Addition of a diol chain extender produces Sartomer Poly bd® 2035, a resinous TPU material with 80 Shore A hardness. Poly bd 2035 TPU resin can be differentiated from other TPUs and TPEs based on a unique structure which contains soft unsaturated diene segments joined by hard isocyanate-based urethane linkages. Like triblock TPEs, the diene-based segments provide sites for sulfur or peroxide vulcanization. Additionally, these materials offer the compatibility with polyurethanes traditionally enjoyed by polyether or polyester-based TPUs. Poly bd 2035 TPU exhibits chemical resistance and improved electrical properties. Application of diene-based TPUs provides the ability to produce rubber articles integrating polyurethane components. By using Poly bd 2035 TPU as a co-curable layer between an uncured rubber compound and a pre-formed polyurethane component, excellent adhesion can be obtained between the dissimilar substrates. Additionally, the co-curable diene-based TPU can be incorporated in a traditional rubber formulation as a functional additive to impart interesting physical properties.