A new kind of supramolecular polymer can be obtained through hydrogen bond interactions of UPy (2-ureido-4[1H]-pyrimidone) units.So it is a new method of polymer modification.Inspired by this

a new kind of polyurethane with UPy units in the main chain was designed.A novel polyurethane chain extender containing UPy units was synthesized through five steps.UPy units were introduced into the main chain of the polyurethane through reacting OH groups with the NCO groups in the prepolymer.The structure was characterized by FTIR and 1H-NMR.The thermal testing results showed that the UPy units aggregated to form microcrystals which melted around 60℃ in the polyurethane.The polyurethane with UPy units in the main chain showed greatly improved mechanical performances compared to the non-UPy counterpart in the tensile testing.The breaking strength was up to 28.6

17.3

15.5

14.9 MPa by using PTMG650

1000

1400

2000 as the soft segment.UPy content in the PU can be adjusted through changing the molecular weight of the soft segment to get PU elastomers with proper performance.