Modified magnesium hydroxide has shown significant advantages in reducing the amount of smoke generated by cable materials during combustion.
Here we analyze the breakthrough progress of this technology in depth from four aspects: technical principles, modification process, practical application and industry prospects.
1. Flame retardant and smoke suppression mechanism
- Basic physical and chemical properties: The molecular formula of magnesium hydroxide is Mg(OH)₂, and the decomposition temperature is as high as 340℃. The thermal decomposition reaction is Mg(OH)₂ → MgO + H₂O↑. Each gram can absorb heat and release water vapor, reduce temperature and dilute oxygen concentration.
- Analysis of smoke suppression mechanism: Modified magnesium hydroxide inhibits smoke generation through gas phase barrier, condensed phase catalysis and free radical capture. The smoke density of PVC cable material with 40% modified magnesium hydroxide is reduced by more than 70%.
2. Core breakthrough of modification technology
- Surface modification technology: The mainstream modification methods include silane coupling agent treatment, stearic acid composite modification and nano-treatment, which can improve dispersibility and flame retardant efficiency.
- Synergistic flame retardant system construction: Typical formula combinations include MH/APP system, MH/CNT composite, and MH/organic montmorillonite, which can improve the limiting oxygen index and reduce smoke density.
3. Industrial application case analysis
- Rail transit cable: The Beijing-Shanghai high-speed rail project uses modified magnesium hydroxide flame retardant cable materials to optimize smoke toxicity, mechanical properties and processing performance.
- Offshore wind power special cable: A European offshore wind farm project uses silane-modified MH TPU sheath material to meet relevant standards and reduce costs.
4. Industry development trends and challenges
- Market demand growth: The global magnesium hydroxide flame retardant market will grow from 2023 to 2030, driven by regulatory restrictions, new national standards and new energy vehicle demand.
- Technical research direction: It is necessary to break through technical bottlenecks such as mechanical property balance under high filling content, ultrafine powder dispersion stability, and environmental protection throughout the life cycle.
Modified magnesium hydroxide reshapes the fire safety standards of the cable industry and is expected to be used in high-end fields in the future. It is a choice for technology upgrading and green manufacturing.