<i>Brassica carinata</i> and <i>Camelina sativa</i> oils as renewable raw materials for producing viscoelastic polyurethane foams

This study aims to evaluate the application potential of unrefined vegetable oils derived from three plant species-<i>Camelina</i> (<i>Camelina sativa</i>), <i>carinata</i> (<i>Brassica carinata</i>), and rapeseed (<i>Brassica napus</i> L. var. <i>napus</i>)-as renewable raw materials for the synthesis of bio-based polyurethane foams. The oils, obtained from crops grown in experimental fields in Greater Poland, were first characterized and then chemically modified <i>via</i> transesterification with triethanolamine to yield hydroxylated derivatives (biopolyols). As a result of this chemical modification, three biopolyols were obtained, characterized by an average molar mass of ∼500 g mol^-1, a hydroxyl number of ∼320 mg KOH per g, functionality of ∼2.8 and a viscosity < 200 mPa s. The biopolyols were then used to produce foam materials with viscoelastic properties. The resulting foams had an apparent density of about 70 kg m^-3, hardness below 2.5 kPa, a support factor (calculated as the ratio of compressive stress at 65% deformation to that at 25% deformation) above 2 and resilience of less than 10%. Additionally, the foaming process of the polyurethane systems containing the newly synthesized biopolyols was analyzed. This study demonstrates the feasibility of utilizing vegetable oils, including non-edible <i>carinata</i> oil, as renewable raw materials for the production of sustainable polymeric materials. The results show that, in addition to the widely studied and commonly used rapeseed oil, both <i>carinata</i> and <i>Camelina</i> oils can also be successfully employed as precursors for the production of bio-based polyurethane foams. Despite differences in fatty acid compositions, the applied synthesis method enabled the preparation of bio-polyols and foams with comparable properties, highlighting the potential of <i>Camelina</i> and <i>carinata</i> oils as sustainable alternatives to conventional rapeseed oil in industrial applications.