Preparation, Morphology and Damping Property of PU/UP Interpenetrating Polymer Networks

Interpenetrating polymer networks (IPNs) composed of acrylate-modified polyurethane (PU)/unsaturated polyester (UP) resin via simultaneous polymerization with various component ratios of PU/UP were prepared. The polymerization processes of IPNs were traced through infrared spectrum (IR) techniques, by which the phase separation in systems could be controlled effectively. Results for the morphology and miscibility among multiple phases of IPNs, obtained by transmission electron microscope (TEM) indicated that the domains between two phases were constricted in nanometer scales. The dynamic mechanical thermal analyzer (DMTA) detection results revealed that the loss factor (tanδ) and loss modulus (E") increased with the polyurethane amounts in system, and the peak value in curves of tanδ and E" appeared toward low temperature ranges. Maximum tanδ values of all samples were above 0.3 in the nearly 50℃ ranges. Also, the mechanical properties of PU/UP IPNs were studied in detail.