Brassica carinata and Camelina sativa 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—Camelina (Camelina sativa), carinata (Brassica carinata), and rapeseed (Brassica napus L. var. napus)—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 via 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 carinata 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 carinata and Camelina 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 Camelina and carinata oils as sustainable alternatives to conventional rapeseed oil in industrial applications.