Sound insulation and mechanical properties of epoxy/hollow silica nanospheres composites

Abstract The incorporation of inorganic nanoparticles into a polymer is an effective way to improve its performances. It is common sense that tiny bubbles in epoxy resin will seriously affect the mechanical properties of composites. Based on this common sense, building a small space inside the epoxy resin will obtain some exciting results, because the small space could effectively block the propagation path of sound, and build a small space in the epoxy resin through nano hollow particles, it will be realized sound isolation without sacrificing the mechanical properties of the composites. If this assumption is verified, it will open up a new route to prepare sound insulation materials using thermosetting resin. In this work, two types of nanoparticles of equal size of the hollow silica nanospheres (HSN) and solid silica nanospheres (SN) were synthesized via sol-gel method. Epoxy Resin (EP) matrix composites containing these HSN or SN particles were designed and fabricated as sound insulation materials. The sound transmission loss (STL) properties were investigated using the impedance tubes. The sound insulation results showed that the STL values of neat EP and EP/SN composites with SN content of 2.0 vol% were up to 17.2 dB and 33.9 dB, respectively, while the EP/HSN composites with the same content of HSN was raised to 44.3 dB for the 3 mm thickness samples. Simultaneously, the mechanical properties of the EP/HSN composites were also improved as the certain addition of HSN in epoxy matrix. And the EP/HSN composites hold a potential for outstanding performance soundproofing application.