Modification of polyurethane by superfine protein powder

Abstract

AbstractPhysical blending was employed to prepare blend films, using superfine wool powder and polyurethane (PU) resin. Scanning electronic microscope photos showed that wool powder had good compatibility with PU in the solvent N,N‐dimethylformamide. The wool powder was uniformly distributed in the films without apparent agglomeration. In the X‐ray diffraction results, the height of the X‐ray diffraction peak decreased gradually with the addition of the wool powder, which implied that the addition of the wool powder could increase the amorphous ratio of the films. Thermogravimetric analysis indicated that the thermal stability of the PU resin decreased with the increase in the wool powder ratio in it. Additionally, the dynamic mechanical analysis result indicated that the ratio of the wool powder had no significant influence on the soft‐segments, but the dynamic storage modulus of the PU films would increase with the increase in wool powder ratio. In addition, the crystal of the PU was destroyed by the wool powder during the drying process at a certain temperature, and this increased the moving probability of the macromolecule chains in PU. With the increase in the ratio of the wool powder, there was an evident decrease in the stress at break, elongation at break, and breaking energy of the blend films, but the water vapor permeability and moisture regain of the blend polyurethane films increased significantly. POLYM. ENG. SCI. 46:617–622, 2006. © 2006 Society of Plastics Engineers.