Synthesis of starch-based polyether non-isocyanate polyurethane with excellent mechanical and foaming properties

Abstract

Non-isocyanate polyurethane (NIPU) represents a novel class of polymers synthesized via an environmentally friendly process without toxic phosgene and isocyanates. Herein, starch-based polyether non-isocyanate polyurethane with excellent mechanical and foaming properties was prepared. First, a carbamate diol was synthesized via a direct reaction between biomass-derived decanediamine and propylene carbonate without the use of catalysts. Then, the target product was obtained by reacting a carbamate diol with bio-derived liquefied starch polyether polyols. The chemical properties of the product structure were determined using Fourier-transform infrared spectroscopy (FTIR) and ¹H nuclear magnetic resonance (¹H NMR) spectroscopy. The thermal stability, mechanical properties, hydrophilicity and degradability of the material were systematically evaluated. The average molecular weight of the optimized products is 26,000 g·mol⁻¹, the initial decomposition temperature is above 280 °C, and the tensile strength is 15.17 MPa. This polymer features a low water absorption rate (4.24 wt% at equilibrium) and high enzymatic degradability (61.2 % mass loss after 7 days in amylase solution). In addition, the foam derived from NIPU has low thermal conductivity and adjustable compression performance, indicating potential applications in insulation. This study presents a viable strategy for the production of high-performance and biodegradable NIPU utilizing renewable resources, contributing to the advancement of green polymer chemistry and sustainable materials.