The influence of microcapsules with a partially filled structure on the damping properties of an epoxy resin

Liquid viscoelastic polymers are promising materials for vibration damping due to their superior damping properties. However, using liquid polymers as materials for this purpose is challenging because liquid polymers cannot be used as normal materials in their amorphous fluid state. This study reports polyurethane/polyurea (PU/PUA) microcapsules prepared using oil-in-water (O/W) emulsion and interfacial polymerization. The microcapsules were partially filled with silicone oil and used as a damping filler in an epoxy resin specimen. Dynamic mechanical analysis measurements (DMA) were performed to investigate the loss factor tan δ of the epoxy resin blended with the microcapsules. The DMA results indicated that the partially filled structure of the microcapsules could enhance the vibration absorbing property of the epoxy resin specimen, and the maximum loss factor (tan δ) increased from 0.38 to 0.79. The loss factor of the epoxy resin could be controlled by the core volume fraction and the concentration of the microcapsules in the epoxy resin.