Curing behavior and flexural properties of cyanate composites reinforced with rare earth- and silane-modified basalt fibers

Abstract

Herein, basalt fibers (BFs) modified by treatment with (3-aminopropyl) triethoxysilane and lanthanum ethylenediaminetetraacetic acid were used to fabricate BF-reinforced bisphenol A dicyanate ester composites via cast molding, and the effects of the modification method on the surface chemical groups and structures of BFs were determined using a range of instrumental techniques. Both modifications increased the number of functional groups on the BF surface. Silane treatment was shown to increase the BF surface roughness to a greater extent than rare earth treatment. Subsequently, we investigated the curing behavior and mechanical properties of BF-reinforced composites, demonstrating that the curing temperature of bisphenol A dicyanate ester was more effectively lowered by the incorporation of lanthanum-modified BFs than by that of silane-modified BFs. Additionally, the composite containing 12 wt% La-modified BFs exhibited flexural strength and modulus that exceeded those of the composite containing 12 wt% silane-modified BFs (by 15 MPa and 0.6 GPa, respectively), which was ascribed to the higher strength of La-modified fibers and the higher extent of curing and moderate interfacial adhesion of the former composites. In summary, lanthanum ethylenediaminetetraacetic acid was proven to be a more effective modifier than (3-aminopropyltriethoxy) silane for improving the curing behavior and flexural properties of the composites.