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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.

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Two types of laminate composites made of glass fibre/epoxy matrix (EPO_FV) and glass fibre/epoxy modified tri-block copolymer (Nanostrength) matrix (EPONS_FV) were manufactured by compression moulding. Some AFM investigations have been done to identify the Nanostrength dispersion in the epoxy matrix and some DMA analyses have been performed, at different frequencies, to understand the frequency or the strain rate sensitivity of both composites. Compared to EPO_FV, EPONS_FV exhibits a significant frequency/strain rate sensitivity. Impact resistance of the composite was investigated by means of low velocity impact tests. The low velocity impact results indicate that the addition of Nanostrength leads to the improved impact resistance and an increase in absorbed energy, especially at high impact energy level. SEM observations, performed on ion polished samples, reveal the presence of micro-cracks for both composites. Micro-cracks consist of a coalescence of fibre matrix de-bonding. It was also observed that EPONS_FV contains a lower density of microcracks compared to EPO_FV, confirming the fact that the composite with Nanostrength absorbs more energy by Nanostrength micelles cavitation.

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