Synthesis of very Flexible Elastomeric Polyurethane Films with High Elasticity

Thermoplastic polyurethanes (TPUs) are unique family of polyurethanes which they have received considerable attention in recent years both scientifically and industrially. TPUsusually possess a blocky chain structure that hard segments (HSs) and soft segments (SSs) are alternatively put in them.HSs act as physical cross-linking due to hydrogen bonds, impose a part similar to chemical cross-linking in vulcanized polymers, and possess elastomeric properties. But these bondsare not as strong as chemical cross-link and can t retain primary structure of TPU with several loadings. Therefore,structural breakup and consequently residual deformation probably occur, especially in HS domains after the first tensile loading [1, 2]. One of the most efficient methods to rapidly synthesize cured polymer network is photo cross-linking with UV radiation that in which cross-linkings are composed in thepresence of appropriate photoinitiator and reactive diluent [3]. In this work, a series of elastomeric PU (EPU) films with highelasticity were synthesized and their structural permanency was evaluated. Synthesized polyurethane showed high degree of flexibility, elasticity, and structural permanency in successive loadings.