As an important functional filler for wires and cables, chemical magnesium hydroxide has certain limitations in its original state in terms of compatibility, dispersibility and performance with polymer matrices. Through modification, chemical magnesium hydroxide can be optimized in terms of surface properties, particle size structure and other aspects, so that it can be better integrated into the wire and cable material system, and the product quality can be comprehensively improved in terms of flame retardancy, mechanical properties, processing performance and other dimensions, meeting the stringent requirements of modern wires and cables in complex application scenarios.
Surface modification is one of the key paths to optimize the performance of chemical magnesium hydroxide. The untreated chemical magnesium hydroxide has a strong surface polarity, and there is a natural interface difference between it and non-polar or weakly polar polymer materials (such as polyethylene, polyvinyl chloride and other common matrices for wires and cables), which makes it difficult to mix the two uniformly. By treating the chemical magnesium hydroxide particles with surface modifiers (such as coupling agents, surfactants, etc.), a special molecular film can be formed on their surface to reduce the surface polarity and enhance the affinity with the polymer matrix. This modified film is like a bridge, allowing chemical magnesium hydroxide particles to be better dispersed in polymer materials, avoiding agglomeration, making the structure of the entire composite material more uniform and stable, thereby improving the comprehensive performance of wires and cables.
The optimization of particle size and morphology also has a significant impact on the quality of wires and cables. The original chemical magnesium hydroxide particles are large in size and irregular in morphology. When filled into wire and cable materials, they are easy to become stress concentration points, reduce the mechanical properties of the materials, and even scratch the equipment during processing. Through physical means such as grinding and ultrasound or chemical synthesis methods, chemical magnesium hydroxide particles can be refined to a suitable size and their morphology can be controlled to be regular spherical or flake. The refined particles can be more evenly distributed in the polymer matrix, reducing the negative impact on the mechanical properties of the material; and the regular morphology helps to reduce the friction resistance between particles, improve the fluidity of the material, make the wire and cable smoother during processing such as extrusion molding, and improve production efficiency and product appearance quality.
The modified chemical magnesium hydroxide shows better performance in flame retardancy. When wires and cables encounter fire, although unmodified chemical magnesium hydroxide can absorb heat and release water to suppress combustion by thermal decomposition, the water vapor produced by decomposition is easy to form pores inside the material, reducing the density of the material and affecting the flame retardant effect. After the modified chemical magnesium hydroxide, the decomposition is more uniform and stable at high temperature, and the released water vapor can be better accommodated by the polymer matrix to avoid the formation of pores. At the same time, the presence of the modifier can promote the chemical magnesium hydroxide to form a denser carbon layer on the surface of the material. This carbon layer is like a heat insulation barrier, which can not only prevent heat from transferring to the inside, but also isolate oxygen, effectively delay the spread of combustion, and significantly improve the flame retardant grade and fire resistance of wires and cables.
In improving mechanical properties, modified chemical magnesium hydroxide plays an important role. Because the surface modification enhances the interfacial bonding force between chemical magnesium hydroxide and the polymer matrix, the relationship between the two is no longer a simple physical filling relationship, but a synergistic structure similar to "rebar and concrete". When wires and cables are subjected to external forces, stress can be more effectively transferred between chemical magnesium hydroxide particles and the polymer matrix to avoid material cracking or fracture caused by stress concentration. At the same time, the refined and regularized chemical magnesium hydroxide particles can be evenly distributed in the matrix as a reinforcing phase, playing a supporting role similar to a "skeleton", improving the tensile strength, bending strength and impact toughness of the material, making the wires and cables more resistant to pulling and extrusion during installation and use, and extending their service life.
Improved processing performance is another major advantage that modified chemical magnesium hydroxide brings to wires and cables. Unmodified chemical magnesium hydroxide will increase the melt viscosity of polymer materials due to its high surface energy and poor dispersibility, resulting in increased energy consumption, slower extrusion speed, and even die blockage during processing. The modified chemical magnesium hydroxide reduces the interface friction between it and the polymer matrix, improves the fluidity of the material, and makes the melt easier to form in the mold. This means that in the production process of wires and cables, a higher processing speed can be used, the molding cycle can be reduced, and production efficiency can be improved; at the same time, good fluidity helps to obtain products with smooth surfaces and precise dimensions, reduce the scrap rate, and improve the economic benefits of the enterprise.
Modified chemical magnesium hydroxide can also improve the weather resistance and electrical insulation properties of wires and cables to a certain extent. The surface modification layer can block the erosion of chemical magnesium hydroxide particles by external moisture, oxygen and corrosive substances, and prevent chemical changes during long-term use, thereby maintaining the stability of material performance. In addition, the uniformly dispersed chemical magnesium hydroxide particles will not form a conductive channel inside the material, and the modification treatment will not introduce too many impurity ions, so it will not have a negative impact on the electrical insulation performance of wires and cables. On the contrary, due to the optimization of the material structure, the electrical insulation performance is more reliable, ensuring the safe operation of wires and cables in electrical systems.
The modification treatment of chemical magnesium hydroxide optimizes the quality of wires and cables from multiple dimensions. By improving the surface properties, particle size morphology, etc., it enhances the compatibility and dispersibility with the polymer matrix, and achieves comprehensive improvement in flame retardancy, mechanics, processing, weather resistance and other properties. This optimization not only meets the high standards of safety and reliability of wires and cables, but also adapts to the development trend of the modern electrical industry for the continuous upgrading of material performance, and provides solid technical support for the wide application of wire and cable products in construction, power, communications and other fields.
