| abstract |
Aromatic-aliphatic diamines of the formula <IMAGE> in which Ar is an arylene or substituted arylene are useful in preparing thermally stable, rigid, polyamides, polyureas and polyurethanes having a repeating unit of the formula <IMAGE> in which Ar is arylene or substituted arylene, X is -NH- or -O-, n is 0 or 1, and R is a divalent organic radical. Polymers of this invention can be melt-spun into thermally stable fibers. |