Hydrogen bonding,mechanical properties,and surface morphology of clay/waterborne polyurethane nanocomposites

A novel clay/waterborne polyurethane (WPU) nanocomposite was synthesized from polyurethane and saponite organoclay. The clay was organically modified with various swelling agents, the effect of which has been investigated. Hydrogen bonding between organic and inorganic materials was characterized with Fourier transform infrared (FTIR) spectroscopy. The results implied that hydrogen bonding increased when organoclay was added. Mechanical and wear property studies revealed that introducing clay into waterborne polyurethane will enhance the Young's modulus (from 56 to 126 MPa), the maximum stress (from 3.9 to 7.6 MPa), and the elongation at break (from 27.7 to 58.7%) of the nanocomposite by a factor of two, whereas the wear loss will be only one third of the neat waterborne polyurethane. Atomic force microscopy (AFM) was used to analyze the surface morphology of the nanocomposite. An AFM microphotograph showed that the surface of the clay/waterborne polyurethane nanocomposite was smoother when clay was added in waterborne polyurethane. The average roughness (R_a) decreased from 1.00 to 0.12. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1–12, 2005