Synthesis,Characterization and Material Application of Poly(Urea-Imide)s,Part 1

Poly(urea-imide)s (PUIs) were prepared by Diels-Alder (DA) intermolecular polymerization of hexamethylenebis(2-furanmethylurea) (BFU) (1) with various bismaleimides (2a-f). The DA reaction was carried out using 1,4-dioxane as solvent, as well as in bulk, followed by aromatization (dehydration) of poly(tetrahydro phthalimide) intermediates (3a-f) in the presence of acetic anhydride. All the PUIs (3a-f, 4a-f and 5a-f) were characterized by elemental analysis, IR spectral studies and thermogravimetrically. BFU (1) and bismaleimides (2a-f) were polymerized (at 145 ± 10°C) by in situ DA intermolecular reaction into moderately thermally stable PUIs (5a-f), glass fiber and carbon fiber composites without evolution of any byproducts. The prepared composites were characterized by chemical resistance and mechanical properties.