Synthesis of Polyurethanes and Semi‐Interpenetrating Polymer Networks From Oligosaccharides

Oligosaccharides occur naturally in many foods and can also be sourced from industrial solid waste. To enhance their value, two oligosaccharides, raffinose and melezitose, have been reacted with toluene diisocyanate (TDI) to produce polyurethanes. The resulting products vary in form—liquid, gel, or solid gel—depending on the stoichiometric ratio of the starting materials. Both conventional and microwave heating have been employed in the synthesis, with microwave heating proving effective in reducing reaction time compared to conventional heating. The resulting polymers have been characterized using 13 C NMR, FT‐IR, TGA, and DSC to confirm their structural and thermal properties. Additionally, the feasibility of incorporating a second polymer into the oligosaccharide‐based polyurethane, thereby creating a semi‐interpenetrating polymer network, has been demonstrated. Examples include the successful embedding of poly(lactic acid) and poly(vinyl pyrrolidone) within the polyurethane matrix. The newly developed materials reported in this work may be used as bioplastics and potential replacements for petroleum‐based materials.