Study on Polyurethane/MDI-Modified-Organic Montmorillonite Nanocomposites

Polyurethane (PU)/MDI-modified-organic montmorillonite (MOMMT) nanocomposites were prepared by in situ polymerization and intercalation technology. Compared with that of organic montmorillonite (OMMT), the interlayer spacing of MOMMT was increased from 1.50nm to 2.05nm because MDI was grafted on the surface of the silicate layers through reaction between MDI and -OH. The dispersion of silicate layers in PU/MOMMT nanocomposites was better than that of silicate layers in PU/OMMT nanocomposites. Compared with those of PU/OMMT nanocomposites, the tensile strength and tear strength of PU/MOMMT nanocomposites were increased, and the MOMMT showed a higher stiffened effect. Because of the improvement of the dispersion and interfacial interaction, the temperature of initial weight loss of PU/MOMMT nanocomposites was higher than that of PU/OMMT nanocomposites, so PU/MOMMT nanocomposites had better thermal stability.