Synthesis, characterization, and glass fiber reinforced composites of poly(urethane-imide)s

Poly(urethane-imide)s (PUI)s were prepared by the intermolecular Diels-Alder (DA)reaction of 4-methyl-1,3-phenylene-bis(2-furanylmethylthioethylcarbamate) (MPFTC) with various bismaleimides. The DA reaction was carried out in 1,4-dioxane as a solvent as well as in bulk, followed by aromatization of tetrahydrophthalimide intermediates in the presence of acetic anhydride. All the polymers were characterized by elemental analysis, IR spectral studies and thermogravimetry. The PUIs exhibit moderate thermal stability. MPFTC and bismaleimides were polymerized (at 145 - 10°C) by an "in situ" DA intermolecular reaction into moderately thermally stable PUIs glass-fiber composite (i.e., laminates) and were characterized by their chemical resistance and mechanical properties.