New thermoplastic polyurethane elastomers based on aliphatic diisocyanate

• DOI: 10.1007/s10973-016-5923-7
• Publication Date: 2016-10-31T09:38:23Z
• Authors: Andrzej Puszka; Anna Kultys
• Keywords: Shore durometer; Thermoplastic elastomer; Thermal Stability; Thermoplastic polyurethane; Thermogravimetric analysis; Gel permeation chromatography

New segmented polyurethanes (SPURs) were synthesized by one-step melt polyaddition from a poly(oxytetramethylene)diol of $$\overline{M}_{\text n}$$ = 1000 g mol−1 (PTMO) or a poly(hexamethylene carbonate)diol of $$\overline{M}_{\text n}$$ = 860 g mol−1 (PHCD) as soft segments, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane (IPDI), and 2,2′-methylenebis[(4,1-phenylene)methylenesulfanediyl]diethanol (diol E) as an unconventional chain extender. Furthermore, some of SPURs were modified by the addition of a carboxylic group by means of 3-hydroxy-2-(hydroxymethyl)-2-methylpropanoic acid. The effects of the kind and amount of the polymer diol and chain extender used on the structure and properties of the polymers were studied. The polymers were examined by attenuated total reflection Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis (TG), TG–FTIR, differential scanning calorimetry (DSC), Shore A/D hardness and tensile testing. The obtained SPURs were amorphous, colourless, high molar mass materials which showed elastomeric or plastic properties. Their T g s were in the range of −51 to 29 °C. It was observed that the polymers with a PHCD demonstrated a better segmental miscibility (higher T g s), as well as greater hardness and tensile strengths, but smaller elongations at break than PTMO-based ones. All of the polymers exhibited a relatively good thermal stability.