Polyurethanes and a process for their preparation with aromatic diamines having at least one aromatic ring, one of said at least one aromatic ring having thereon at least two alkylthio substituents and at least one amino substituent. An isocyanate prepolymer may be combined with a diamine chain extender of the invention and cured at suitable processing temperatures to form elastomers with good physical properties.
                            聚
氨酯及其用芳香族二胺制备的工艺,芳香族二胺具有至少一个芳香环,其中至少一个芳香环上具有至少两个烷
硫基取代基和至少一个
氨基取代基。 
异氰酸酯预聚物可与本发明的二胺扩链剂结合,并在适当的加工温度下固化,以形成具有良好物理性能的弹性体。