Binary blends of polyether-based polyurethane block copolymer and poly(vinylidene fluoride): Physical and thermal properties

Miscibility and phase behavior studies of thermoplastic polyether-based pol yurethane (TPEU) and poly(vinylidene fluoride) (PVF2) blends were investiga ted by means of Fourier transform infrared spectroscopy (FTIR), differentia l scanning calorimetry (DSC), thermogravimetry (TGA), and mechanical behavi or. TPEU based on 1,6-diisocyanohexane (HDI), 1,4-bu-tanediol (BD), and 100 0 molecular weight poly(tetramethylene oxide) (PTMO) was synthesized. It wa s shown by FTIR that the addition of PVF2 to TPEU disrupted the intermolecu lar interactions between soft and hard segments in TPEU, and the interactio ns between an urethane carbonyl and protons of PVF2 was stronger than that between urethane carbonyl and urethane NH. It was found that PVF2 was immis cible with soft segment (PTMO) and miscible with hard segment and the degre e of phase purity of the soft domain increased with increasing PVF2 content . The presence of a specific intermolecular interaction between the hard se gment and PVF2 was suggested by an observed systematic depression in the me lting point of the PVF2 component. It was also found that the thermal stabi lity, tensile strength, and Young's modulus increased proportionally to PVF 2.