Bio-based hyperbranched polyurethane/clay nanocomposites: adhesive, mechanical, and thermal properties

The unison of vegetable oil-based hyperbranched polymers with nanotechnology can unhook myriad of avant-garde applications of such materials. Thus Mesua ferrea L. seed oil-based hyperbranched polyurethane (HBPU)/clay nanocomposites and their performance, with special reference to adhesive strength, are reported for the first time. The nanocomposites of the hyperbranched polyurethane with organically modified nanoclay were obtained by ex situ solution technique and cured by bisphenol-A-based epoxy with poly(amido amine) hardener system. The partially exfoliated and well-distributed structure of nanoclay was confirmed by XRD, SEM, and TEM studies. FTIR spectra indicate the presence of H-bonding between nanoclay and the polymer matrix. Two times improvement in the adhesive strength and scratch hardness, 10 MPa increments in the tensile strength and 112 degrees C more thermo-stability have been observed without much affecting the impact resistance, bending, and elongation at break of the nanocomposites compared to the pristine epoxy modified HBPU system. Thus, the resulted nanocomposites are promising materials for different advanced applications including adhesive. Copyright (C) 2009 John Wiley & Sons, Ltd.