Keratin feathers as a filler for rigid polyurethane foams on the basis of soybean oil polyol

Soybean oil-based rigid polyurethane foams (RPUFs) were successfully reinforced with different weight ratios (0.1 wt%, 0.5 wt%, 1.5 wt%) of chicken feathers (CF) filler. The resulting foams were evaluated by their processing parameters (processing times, absolute viscosities), chemical structure (FTIR analysis), morphology (SEM analysis), mechanical properties (compressive test, three point bending test), viscoelastic behavior (DMA test), thermal property (TGA analysis, thermal conductivity) and application properties (surface hydrophobicity, water absorption, dimensional stability). Scanning electron microscopy (SEM) results showed that the morphology of modified foams is significantly affected by the chicken feathers content, which resulted in inhomogeneous, irregular, and large cell shapes and further affected the physical and mechanical properties of resulting materials. The results showed that in comparison with unfilled foam, compositions modified with 0.1 wt% of CF provide greater compression strength (220 kPa measured parallel) and lower thermal conductivity (0.027 W/m·K). The results obtained in this study suggest that the introduction of CF over a certain optimal level has a negative effect on the cell morphology, which leads to deterioration of physico-mechanical properties of the modified foams. Thermally stable, water-resistant, and environmentally friendly composite foams may provide a promising development for designing new functional materials that can be applied in various fields.