Improved dielectric and mechanical properties of silica/epoxy resin nanocomposites prepared with a novel organic–inorganic hybrid mesoporous silica: POSS–MPS

• POSS–MPS are synthesized by grafting MPS with a layer of G-POSS.
• POSS–MPS/EP nanocomposites exhibit a lower κ because of voids arising from POSS–MPS.
• POSS–MPS/EP nanocomposites exhibit improved mechanical and thermal properties.
• The properties of composites are affected with the content of POSS–MPS.

The novel organic–inorganic particles (denoted POSS–MPS) were synthesized by the reaction of amino-functionalized mesoporous silica (NH2-MPS) with a wormhole framework structure and glycidyl polyhedral oligomeric silsesquioxane (G-POSS), and were employed as reinforcing agents to prepare POSS–MPS/epoxy resin (EP) nanocomposites. The retaining mesoporous structure of POSS–MPS was verified by TEM and N2 adsorption–desorption. The excellent improvement in dielectric properties, thermal properties and mechanical properties of the POSS–MPS/EP nanocomposites is ascribed to increase of voids volume and reinforcement of interfacial interaction between organic and inorganic phase in the composites. The POSS–MPS/EP nanocomposites containing 5 wt% of POSS–MPS showed a lower dielectric constant (κ=3.66) and loss factor (tan δ=0.017) in comparison to pristine EP with the value of 4.03 and 0.031, respectively. Moreover, the composites exhibited 23.8%, 43.5%, 159.8% and 59.8% enhancement in tensile strength, tensile modulus, elongation at break and glass transmission temperature (Tg) in comparison to pristine EP, respectively. The results manifested that introduction of POSS–MPS improved the mechanical properties, heat resistance and dielectric properties of EP.