Novel polyetherurethaneurea elastomers based on α,α,α′,α′‐tetramethyl‐m‐xylenediisocyanate: Synthesis, characterization, processability, and hydrolytic stability

A series of novel polyetherurethaneurea elastomers based on m‐TMXDI, polyether macrodiols containing 4, 6, 8, or 10 methylene groups between the ether linkages, and aliphatic and aromatic diamines was prepared by two‐step solution polymerization. All the materials were thermally processable at 120–160°C except one that was solvent‐castable. Mechanical properties and hydrolytic stability (at neutral pH) were found to depend on the macrodiol and chain extender. Poly(tetramethylene oxide)‐based polyetherurethaneureas that were chain‐extended with primary aliphatic diamines, other than 1,3‐propanediamine, exhibited significantly better mechanical properties than those chain‐extended with secondary aliphatic or aromatic diamines. The mechanical properties and hydrolytic stability of polyetherurethaneureas containing poly(hexa‐, octa‐, or decamethylene oxide) and 1,6‐hexamethylenediamine were considerably better than those containing 1,2‐ethylenediamine. The hydrolytic stability increased with the increasing C/O ratio of the macrodiol. With poly(hexamethylene oxide)‐based materials, the phase separation between soft and hard domains was higher than that of the other materials as determined by DSC. © 1993 John Wiley & Sons, Inc.