Damping analysis of polyurethane/polyacrylate interpenetrating polymer network composites filled with graphite particles

The graphite-filled polyurethane/poly(methyl methacrylate-butyl methacrylate) (PU/P(MMA-BMA)) semi-interpenetrating polymer networks (IPNs) were synthesized by sequential method. The influences of graphite particle content and size on the 60/40 PU/P(MMA-BMA) IPNs were studied. The damping properties of IPN composites were evaluated by dynamic mechanical thermal analysis (DMA) and cantilever beam resonance methods. The mechanical performances were investigated using tensile and hardness devices. DMA results revealed that the incorporation of graphite particles improved damping properties of IPNs significantly. The 5% graphite-filled IPN composite exhibited the widest temperature range and the highest loss factor (tan delta) when the test frequency was 1 Hz. As to the damping properties covering a wide frequency range from 1 to 3,000 Hz, the addition of graphite particles broadened the damping frequency range (Delta f, where tan delta is above 0.3) and increased the tan delta value of IPNs. Among them, the composite with 7.5% graphite showed the best damping capacity. And the hardness and the tensile strength of IPN composites were also improved significantly. POLYM. COMPOS., 2013 (C) 2013 Society of Plastics Engineers