Four novel polyurethanes (PUs) containing 2,6-bis(4-hydroxybenzylidene) cyclohexanone hard segments with four diisocyanate, namely, 4,4 0 -diphenylmethane diisocyanate, toluene 2,4-diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, were prepared. Structural elucidation and thermal characterization of these PUs were done by Fourier transform infrared, UV, and fluorescence spectroscopy, 1 H-NMR, 13 C-NMR, and differential thermal analysis/thermogravimetric analysis. All of the PUs contained domains of semicrystalline and amorphous structures as indicated by X-ray diffraction. PUs were soluble in polar aprotic solvents such as N-methyl-2-pyrrolidone, dimethylformamide, and dimethyl sulfoxide. Acoustic properties were calculated from the group contribution method.