Novel Rigid Polyisocyanurate Foams from Synthesized Biobased Polyester Polyol with Enhanced Properties

Novel rigid polyisocyanurate foams (PIR) produced from different polyesters polyols, such as a conventional fossil-based polyester polyol (as a reference) and a synthesized sorbitol-based polyester polyol, have been fully investigated. PIR foams were prepared by gradual substitution of the fossil-based polyester polyol by the biobased polyester polyol until a full substitution with adapted conditions. The foaming reactive process was monitored continuously to evaluate the impact of the temperature, the isocyanate trimerization, and the biobased polyester polyol on the foaming rate. The different foams were fully characterized and compared. Foams with 25 wt % of biobased polyester polyol show an impressive increase of 96% and 142% of their respective longitudinal and transversal Young’s modulus compared to the equivalent fossil-based reference. Mechanical properties of such foams are linked to their morphologies as they presented significant smaller cell sizes compared to the reference for a similar apparent density (30 kg/m3). The foams thermal conductivity, degradation, and flammability were also studied. Partially biobased foams show remarkable thermal conductivities until 22 mW/m K, whereas conventional values of equivalent fossil-based foams range from 23 to 30 mW/m K. Foams prepared with fully and potentially biobased polyol present the highest thermal resistance.