抄録
Polyurethane (PU) films and foams were prepared from bean-curd refuse (BCR) and diphenylmethane diisocyanate (MDI), from the viewpoint of recycling of bio-based resources and developing of environmentally-friendly polymers. Powdered BCR was used as a part of polyol. Although BCR-PU is obtained by a solid-liquid reaction between BCR and MDI, FT-IR measurements show a shift of the C=O stretching band with BCR content, which indicates the formation of the urethane bond between BCR and MDI. Stress at break (σb) and Young's modulus (E) of BCR-PU's increased with increasing reaction time and BCR content of polyol (BCR/Polyol). σb, and E decreased with increasing particle size of BCR. These facts indicate that cross-link density increases with increasing the amount of BCR powder and that BCR powders act as hard segments in PU. On the other hand, stress at 10% strain (σ10) of PU foam decreased with increasing BCR content. It was found that σ10 depends on the apparent density of PU foams more than on BCR content in total polyol.
