Effects of silane‐modified nano‐CaCO3 particles on the mechanical properties of carbon fiber/epoxy (CF/EP) composites

In this study, the effects of silane‐treated nano‐CaCO3 particles on the flexural, Mode‐I, Mode‐II and interlaminar shear strength (ILSS) properties of carbon fiber/epoxy composites are investigated experimentally. The surface of nano‐CaCO3 particles is treated with a silane coupling agent, namely, (3‐Glycidyloxypropyl) trimethoxysilane (GPTMS). Three‐point bending, double cantilever beam (DCB), end‐notch flexure (ENF), and short beam shear (SBS) tests are carried out on the prepared composite specimens according to the relevant ASTM requirements. The results show that with the dispersion of 5 wt% silane‐treated nano‐CaCO3 particles the flexural modulus, flexural strength, Mode‐I fracture toughness, Mode‐II fracture toughness, and ILSS values can be enhanced by 16.8%, 13.6%, 25.7%, 19.6%, and 19.8%, respectively, compared to reference composites. The storage modulus is also increased by about 15.3% with the silane‐treated nano‐CaCO3 particles. The silane‐treated nano‐CaCO3 particles had no significant effect on the glass transition temperature of the composites. Effects of untreated and treated CaCO3 particles on the mechanical propert