The influence of soft segments on some properties of new transparent segmented polyurethanes

This work describes the synthesis and structure of the new segmented polyurethanes (SPURs) formed from an aliphatic diisocyanate [1,1-methanediylbis(4-isocyanatocyclohexane] (Desmodur W-(R)) and unconventional sulfur-containing chain extender [2,2-methylenebis([4,1-phenylene]methylenesulfanediyl)diethanol]. Soft segments were poly(oxytetramethylene)diol of (M) over bar (n)=1000g/mol (PTMO) or poly(hexametylene carbonate)diol of (M) over bar (n)=860g/mol (PHCD). For all the polymers, the structure, physicochemical, thermal, and mechanical properties were determined. In addition, for selected polymers, optical properties (refractive index and transparency), adhesive properties, and antimicrobial activity were also determined. The type and amount of soft segment used for the synthesis of SPURs had a significant effect on the properties of the polymers. SPURs from PHCD are characterized by higher glass transition temperatures, molar masses, hardness (up to 91/50 degrees Sh in scale A/D), and tensile strengths (up to 36.5MPa) but lower elongations at break compared with the SPURs with PTMO. The tests of adhesion and optical properties showed that the PHCD-based SPUR was characterized by higher value of refractive index, transparency, and more than three times the adhesive strength than the PTMO-based SPUR. Antimicrobial activity studies showed that the SPUR presence in the medium inhibited proliferation of both Gram-positive and Gram-negative bacteria. Copyright (c) 2017 John Wiley & Sons, Ltd.