Study On Mechanical Properties Of Modified Basalt Fiber And Its Composite

As a kind of advanced inorganic high-performance fiber, basalt fiber has excellent mechanical properties, thermal stability and chemical resistance. Currently, basalt fiber has replaced to some extent of glass fiber, PBO fiber and carbon fiber as reinforcement for fiber reinforced resin matrix composites. It is much likely that basalt fiber turns into the fourth most used fiber, which has high strength and modulus. But like other high-performance fibers, basalt fiber's inert surface, which would result in poor adhesion to the resin matrix, reduces the mechanical properties of the composites. Hence, there is a lot of attention paid to the methods of basalt fiber surface modification.In this work, it was expected that basalt fiber and its composite could show higher mechanical properties through surface modification with coating. Meanwhile, higher thermal stability was also needed, which could guarantee basalt fiber reinforced polymer composite to have lower mass loss and higher residual interlaminar shear strength after high-temperature tests.Composites, which were reinforced with basalt fibers coated by different nano-particle modified film-forming agents and sizings, were prepared through an optimized thermal compression molding process. Through comparison of interlaminar shear strengths, high-temperature mass losses and residual interlaminar shear strengths, it was shown that the composite which was reinforced with the basalt fiber coated by SiO₂ modified sizing exhibited the best interlaminar shear strength, and the composite reinforced with the basalt fiber coated by ZrO₂ had the lowest mass loss and the highest residual interlaminar shear strength.The effects of diameter and concentration of nano-SiO₂ particles on basalt fiber's surface energy, mechanical properties and composite's mechanical properties were studied. Additionally, composites prepared by ZrO₂ and CeO₂ modified phenolic resin was tested. It was concluded that 0.2wt% concentration and 350nm SiO₂ particles could best improve the basalt fiber's surface polarity and composite's interlaminar shear strength. Composites prepared by ZrO₂ and CeO₂ modified phenolic resin had an equal interlaminar shear strength with the composite reinforced with the original basalt fiber, and a lower residual interlaminar shear strength than that of composites reinforced with the basalt fiber coated by ZrO₂ and CeO₂ modified sizing. However, composites prepared by ZrO₂ and CeO₂ modified phenolic resin presented the lowest mass loss in high-temperature tests.