Modified epoxy with monodispersed solvent -free nano SiO₂ fluid

The solvent -free nano SiO₂ fluid was prepared with nanoparticle SiO₂ as the core, N,N-didecyl-N-methyl-N-(3-trimethoxysilylpropyl) ammonium chloride (SID3392) as the necklayer and poly(ethylene glycol) 4-nonylphenyl3-sulfopropyl ether potassium salt (PEGS) as the canopy. The solvent -free nano SiO₂ fluid is a Newtonian fluid with low viscosity at room temperature, and its viscosity is 4.3 Pa·s at 26.5 ℃. The mass fraction of SiO₂ in the solvent -free nano SiO₂ fluid is 13.65%.The solvent -free nano SiO₂ fluid is loaded in the epoxy matrix to prepare solvent -free nano SiO₂ fluid/epoxy composites. The TEM results confirm that the solvent -free nano SiO₂ fluid disperses well in the epoxy matrix. DSC test shows that the solvent -free nano SiO₂ fluid can decrease the curing temperature of the epoxy. When the content of solvent -free nano SiO₂ fluid in the composites reaches up to 2.5wt%, the impact properties of the epoxy is improved up to 164.7%. The glass transition temperature is improved by 15.4 ℃. The SEM results of fracture surface also confirm that solvent -free nano SiO₂ fluid can improve the toughness of epoxy.