Recently, the R&D team of ZKXJ Basalt Fiber Technology Company has made progress in the research of high performance of basalt fiber. In view of the characteristics of basalt fiber as an insulating material, the researchers prepared a functional sizing agent based on conductive nanocomposite materials, and optimized the sizing agent formula by a full experimental method. On this basis, using basalt ore as raw material, combined with the process of coating the fiber with sizing agent during the preparation process, the conductive basalt fiber was prepared in batches on a 50-hole drawing equipment built by the laboratory.
Basalt fiber is a filamentous material made from natural basalt ore, which is crushed, melted, wire drawn and coated with sizing agent. This type of fiber has good thermal stability, mechanical properties and corrosion resistance, so it is widely used in transportation, construction and marine fields. Basalt fiber itself is an insulating material and does not have conductive properties. However, during the production and use of the material, the friction between the fibers will generate static electricity, which affects the convenience of fiber bundling, processing and application, and also limits its use in high-performance materials.
Studies have shown that the functional sizing agent developed has good dispersion stability and good electrical properties, and its electrical conductivity exceeds 200 μS/cm. Observation of the micro-morphology of the material shows that the sizing agent has good film-forming properties on the surface of basalt fiber , The thickness is about 500 nm, the sizing agent coating makes the basalt fiber macroscopically transformed from an insulator to a conductor, and the conductivity exceeds 10 S/cm, which meets the application of the material in the field of antistatic; it is comparable to the basalt fiber without the sizing agent. Compared with the conductive basalt fiber, the monofilament tensile strength is increased by 20%. The related mechanism research has found that the sizing agent can effectively reduce the stress concentration on the surface of the basalt fiber through crack blunting and bridging, and it has a certain effect on the structural defects on the fiber surface. Repair function.
In addition, this research uses basalt fiber fabric as raw material, and directly grows carbon nanotubes on its surface by chemical vapor deposition without additional catalysts, and uses the fiber material as the reinforcing phase to effectively composite with the polymer matrix to prepare Polymer nanocomposite materials, research the electromagnetic shielding performance of composite materials. The results show that basalt fibers will precipitate nanoparticles with a size of 10-100 nm on the surface at high temperatures, and the crystallinity of the nanoparticles will increase significantly as the processing temperature increases. Under high temperature conditions, the precipitated nanoparticles can be used as catalysts to achieve in-situ controlled growth of carbon nanotubes. The direct growth of carbon nanotubes on the basalt fiber fabric solves the problems of difficulty in dispersing and agglomeration of nanoparticles in the polymer matrix, and provides a new method for the efficient preparation of nanocomposites. The study of the electromagnetic shielding performance mechanism of nanocomposites found that the nano-micro multilayer structure in the composite system improves the probability of multiple reflections of electromagnetic waves inside the material. The inside of the material is through charge transfer, dipole polarization, and capacitive double layer structure. The absorption of electromagnetic waves and the synergistic effect produced by multiple reflections make nanocomposite materials have better electromagnetic shielding performance.