As versatile biomass-based diol precursors, N,N'-1,2-ethanediylbis-(4-hydroxy-pentanamide) (1) and 4-hydroxy-N-(2-hydroxyethyl)-pentanamide (2) are potential monomers to synthesize novel polyurethanes through adding di-isocyanates. This study reported the structural analysis and molecular behavior of polyurethanes obtained from polymerization of the diol precursors with aliphatic and aromatic di-isocyanates (hexamethylene diisocyanate, HDI (3), and phenyl-diisocyanate, PDI (4)) in (N,N-dimethylacetamide (DMA) solvents with triethylamine (TEA) catalysts.¹H-NMR,¹³C-NMR and Elemental Analysis confirmed structure of the polyurethanes built from both diols and di-isocyanates and FTIR indicated interaction among polyurethane molecules showed at lower wave numbers such as 2855-2976 cm^-1for hydrogen-bonded NH groups and 1621-1643 cm^-1for hydrogen-bonded C=O groups. Furthermore a study on influence of the inter-and intra-molecular hydrogen bonding on the thermal and mechanical properties of the polyurethanes would be an interesting investigation for the next study.