Preparation, characterization, and properties of castor oil-based flexible polyurethane/Cloisite 30B nanocomposites foam

The present study represents the synthesis of flexible polyurethane nanocomposite foam using Cloisite 30B nanoclays varying at 1, 2, and 3wt%. The polyurethane nanocomposite foam formulated with 50:50 weight ratio of synthetic polyether polyol and renewable resource-based castor oil. The progress of isocyanate reaction and formation of bidentate urea through H-bonding in the polymeric matrix phase were confirmed from Fourier transform infrared analysis. The surface morphology of the nanocomposite foams was examined by scanning electron microscopy and X-ray diffraction analysis. Polyurethane nanocomposite foam displayed exfoliated structures at 3wt% Cloisite 30B. The thermal and mechanical properties were also studied to report the impact of Cloisite 30B in biobased flexible polyurethane foam. Enhanced thermogravimetric outcome signified higher thermal stability of polyurethane nanocomposite foam as compared to polyurethane foam. Further, improvement of the soft segment glass transition temperature (T-g) confirmed the role of Cloisite 30B in the phase separation behavior between the hard segment and soft segment in nanocomposite foams. A significant enhancement in the mechanical strength with incorporation of a small amount of Cloisite 30B nanoclay to the flexible polyurethane foam allows it for various low cost applications.