This study reports the fabrication and performance of sustainable polyurethane (PU) films based on wheat starch
(native NS, modified MS), bio-polyols (1,3-propanediol PD, glycerol Gly), and polymeric diphenylmethane diisocyanate
(pMDI). NS was successfully modified with isophorone diisocyanate, confirmed by Fourier transform
infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance (13C NMR). Various PU films were prepared
using NS, PD or Gly, MS and pMDI. For comparison, reference films were also synthesized without MS. PU films
were analyzed from the viewpoint of their chemical, thermomechanical and flexural properties, and microstructural
morphology. FTIR spectra demonstrated the total consumption of NCO groups, while the scanning
electron microscopy micrographs of the films revealed that MS addition promoted the interactions between the
compounds, enhancing in consequence their mechanical and thermomechanical performance. The study supported
the suitability of functionalized carbohydrates to substitute petrochemical compounds in the synthesis of
more environmentally-friendly PUs.
