Synthesis and characterization of polyurethane rigid foams from polyether polyols with isosorbide as the bio-based starting agent

In this study, with the isosorbide as bio-based starting agent, a series of bio-based polyether polyols with different hydroxyl values were synthesized and used to prepare polyurethane rigid foams (PURF). The structures of as-synthesized polyols were studied by FT-IR and ¹H NMR methods. The thermal properties, mechanical properties, microscopic morphology, thermal conductivity and dimensional stability of PURF have been characterized by several physico-chemical and ASTM methods. The initial decomposition temperature T_5% and the maximum decomposition temperature T_max for PURF from isosorbide-based polyols with 458 mg KOH/g hydroxyl value are about 312 °C and 354 °C, improved 61 °C and 75 °C comparing with the PURF from 1,2-propanediol-based polyols. The maximum compressive strength of PURF from isosorbide-based polyols is 141 kPa, comparing with 118 kPa of PURF from 1,2-propanediol-based polyols. Meanwhile, the dimensional stability of PURF from isosorbide-based polyols has been improved twofold, and the water absorption was obviously reduced by 50%. All these results suggest that polyols of isosorbide-based starting agent should be promising feedstock for PURF with high performance.