Novel thermoplastic polyhydroxyurethane elastomers as effective damping materials over broad temperature ranges

• Published in: European polymer journal 2016-11, Vol.84, p.770-783
• Main Authors: Beniah, Goliath, Liu, Kun, Heath, William H., Miller, Matthew D., Scheidt, Karl A., Torkelson, John M.
• Format: Article
• Language: English
• Subjects: Chains; Damping; Damping material; Divinylbenzene; Dynamic mechanical analysis; Elastomers; Elongation; Fourier transforms; Hydrogen bonding; Hydroxyl groups; Infrared spectroscopy; Modulus of elasticity; Nanostructure; Non-isocyanate; Polyhydroxyurethane; Polytetrahydrofuran; Polyurethane; Polyurethane resins; Scattering; Segments; Separation; Small angle X ray scattering; Spectroscopic analysis; Temperature; Tensile properties; Tensile strength; Thermoplastic resins; Thermoplastics; Urethane thermoplastic elastomers
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2016.05.031

[Display omitted] •Non-isocyanate, thermoplastic PHU elastomers were made with PTMO soft segment.•Segmented PHUs are nanophase-separated with tunable mechanical properties.•PHUs have broad interphases with a wide range of local composition.•High tan δ (⩾0.30) over broad and tunable temperature ranges observed via DMA.•These PHUs are useful as broad-temperature-range damping materials. Non-isocyanate thermoplastic polyhydroxyurethane (PHU) elastomers were synthesized from cyclic carbonate aminolysis using polytetramethylene oxide (PTMO) as soft segment and divinylbenzene dicyclocarbonate and three diamine chain extenders as hard segment with a range of hard-segment content. Characterization was done via Fourier transform infrared spectroscopy, small-angle X-ray scattering (SAXS), uniaxial tensile testing, and dynamic mechanical analysis (DMA). SAXS reveals that these PHUs possess nanophase-separated morphology with 10–20nm interdomain spacings. These PHUs display elastomeric response and tunable tensile properties with Young’s modulus ranging from 27 to 200MPa, tensile strength from 0.3 to 9.7MPa and elongation at break ranging up to greater than 2000%. DMA reveals that nanophase separation in these PHUs is accompanied by broad interphases having a wide range of local composition; this nanophase separation differs significantly from that manifested by thermoplastic polyurethane elastomer (TPU) due to hydrogen bonding of hydroxyl groups in the hard segments to the PTMO soft segment. These PHUs show very good damping performance with tan δ⩾0.30 over broad temperature ranges (⩾60°C), which are tunable through simple variation of hard-segment content and chain extender structures.