Superior Properties of Polyurethane Elastomers Synthesized with Aliphatic Diisocyanate Bearing a Symmetric Structure

Polyurethane elastomers (PUEs) containing <i>trans</i>-1,4-bis­(isocyanato­methyl)­cyclohexane (1,4-H₆XDI) have been synthesized by polymerizing 1,4-H₆XDI with poly­(oxytetra­methylene) glycol and 1,4-butanediol. The molecular aggregation state and mechanical properties of these PUEs have been compared with those exhibited by PUE analogues made of MDI and diols. The hard segment chains in the 1,4-H₆XDI-based PUEs are found to readily crystallize and form strong hydrogen bonds due to a high symmetry of 1,4-H₆XDI molecule. Consequently, the 1,4-H₆XDI-based PUEs exhibit well-organized hard segment domains. This leads to their generally superior mechanical properties as compared to those of the well-known MDI-based PUEs. 1,4-H₆XDI’s lack of aromatic moieties is expected to greatly enhance color stability of resulting PUEs. All the above features suggest 1,4-H₆XDI could replace MDI in a range of applications