Investigation of toughening effect of biomass‐derived SiCB on basalt fiber‐reinforced unsaturated polyester composites

Abstract Fiber‐reinforced polymer composites are outstanding lightweight structural materials, so that they are widely used in automotive, marine, medical, defense, and aerospace fields. However, when subjected to structural loads, they are prone to failure due to their inherent brittleness and the susceptibility to delamination, which can lead to the loss of the load‐bearing capacity of composite materials. This article proposes an effective solution of innovatively using the silicon carbon black, a kind of sustainable green biomass material derived from rice husks, to toughen the composites. When the content of silicon carbon black (SiCB) added to the composites is 1.5 wt%, the maximum values of flexural strength, bending energy absorption, and the mode II interlaminar fracture toughness values are 333 MPa, 6.10 J, and 1591 J/m², respectively, corresponding to the improvement percentage of 138%, 120%, and 216%. The addition of SiCB significantly improved the bending properties and the mode II interlaminar fracture toughness of composites. The toughening mechanisms of SiCB were studied based on the fracture surface morphologies of the composites.