Chemorheology and properties of a thermoset PU/clay nanocomposite system

Understanding the chemorheology of a nanocomposite system is crucial to gain a fundamental understanding of the processability and structure-property relationships for the system. The chemorheology and properties of a PU/clay nanocomposite system comprising organically modified clay were investigated. An optimum [NCO]/[OH] ratio showing a maximum tensile strength was determined for the PU system. The effect of clay content on the tensile strength of the PU/clay nanocomposite was investigated. Differential scanning calorimetry and Fourier transform infrared spectroscopy were used to study the polymerization kinetics of the PU/clay nanocomposite system. The polymerization rate of the PU/clay nanocomposite system was faster than neat PU system. The rheological property change during isothermal and dynamic polymerization of the PU/clay nanocomposite system was monitored using a parallel plate rheometer, and used to analyze chemorheology of the system. The glass transition temperatures of the PU/clay nanocomposites were determined by thermomechanical analysis. The thermal decomposition behavior of the PU/clay nanocomposites was measured using thermogravimetric analysis. Structural analyses of the PU/clay nanocomposite were performed by X-ray diffractometer and transmission electronic microscope. The gelation time of the PU/clay nanocomposite system was shorter than neat PU system