Influence of cell type and skin-core structure on the tensile elasticity of the microcellular thermoplastic polyurethane foam

Abstract

In this work, the foaming process was employed to achieve lightweight thermoplastic polyurethane materials, and then the hysteresis and residual strain of corresponding materials in the tensile process were quantitatively calculated. In order to study the deformed mechanism, the influences of cell type and skin-core structure on the tensile elasticity of thermoplastic polyurethane foam were investigated. The open-cell thermoplastic polyurethane foam exhibited much lower hysteresis and residual strain compared to thermoplastic polyurethane film without cell structure, which demonstrated that the open-cell structure benefited to the tensile elasticity. In the case of closed-cell thermoplastic polyurethane foam, it had lower hysteresis and residual strain than thermoplastic polyurethane film; however, higher value than the thermoplastic polyurethane film can be observed beyond 100% strain, resulting from the stress concentration in the skin-core structure. Consequently, the hysteresis phenomenon can be improved by adjusting the ratio of skin-core structure. Moreover, the influence of density on the elasticity of the open-cell thermoplastic polyurethane foam was also discussed in this study.