Effects of Structure and Composition on the Transparence and Mechanical Properties of Polyurethanes

The behaviour of crystalline phase separation in soft and hard blocks greatly influences the transparence and mechanical properties of polyurethanes. By using dicyclohexylmethane diisocyanate, poly(propylene oxide) and 1,3-butylene glycol, the flexible transparent polyurethanes were synthesized that is fully amorphous. When the hard segment content is 47% (wt), they show very good transparence and mechanical properties with transparency 93%, tensile strength 18 MPa, elongation at break 358%, Shao-A hardness 90 and non-yellowing after a time.