Polyurethane films prepared with isophorone diisocyanate functionalized wheat starch

Open Access

Abstract

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. ; The authors acknowledge the financial support of Lantm¨annen Forskningsstiftelse (Grant No. 2017H011), University of the Basque Country (UPV/EHU) (GIU18/216 Research Group) and Basque Government (PIBA2020-1-0041). Authors are also grateful to the SGIker units of the UPV/EHU. Dr Hosseinpourpia also wishes to thank the support of Formas, Swedish Research Council for Sustainable Development (Future research leaders, Grant No. 2018-00637). ; info:eu-repo/semantics/publishedVersion