Study on the flame retardant properties of magnesium hydroxide modified polypropylene expanded graphite composites
In the field of material science, polypropylene (PP) is a widely used thermoplastic, and the improvement of its flame retardant properties has always been a hot research topic. In particular, Magnesium Hydroxide (Mg(OH)_2), as an efficient halogen-free flame retardant, has been widely studied for its environmental friendliness and high flame retardant efficiency. This article will explore the flame retardant properties of magnesium hydroxide modification in polypropylene expanded graphite (EG) composite materials, and the impact of expanded graphite particle size on this property.
Effect of magnesium hydroxide modification on composite materials
The addition of magnesium hydroxide significantly improves the flame retardant properties of PP. Through modification treatment, such as surface coating, the dispersion of magnesium hydroxide in the PP matrix can be further improved, and its compatibility with the matrix can be enhanced, thereby improving the flame retardant efficiency. Effect of expanded graphite particle size on flame retardant properties of composite materials
The particle size of expanded graphite directly affects its dispersion uniformity in the PP matrix. EG with a smaller particle size can increase the contact area with the polymer matrix, improve expansion efficiency, and form a more effective insulating carbon layer, thereby enhancing flame retardant properties. Synergistic flame retardant effect of magnesium hydroxide and expanded graphite
The combined use of magnesium hydroxide and expanded graphite not only creates a physical barrier, but also achieves a synergistic flame retardant effect through endothermic decomposition reaction and water vapor dilution, significantly improving the flame retardant performance of PP. Mechanism of action analysis
Under high temperature conditions, the endothermic decomposition of magnesium hydroxide and the rapid expansion of EG work together to form a heat-insulating and oxygen-insulating carbon layer, which effectively inhibits the combustion process of PP. At the same time, this synergistic effect also improves the thermal stability and mechanical properties of the composite. Experimental and theoretical research
Through testing methods such as limiting oxygen index (LOI), vertical combustion test (UL-94), thermogravimetric analysis (TGA) and scanning electron microscope (SEM), the resistance of PP composite materials modified by EG and magnesium hydroxide with different particle sizes was evaluated. influence on combustion performance. Combined with theoretical simulations, the expansion kinetics of expanded graphite and the mechanism of magnesium hydroxide modification were deeply discussed. The application of magnesium hydroxide modification in polypropylene expanded graphite composite materials provides an effective way to improve the flame retardant properties of PP. The optimization of expanded graphite particle size and the synergistic effect of magnesium hydroxide not only improve the flame retardant efficiency of the material, but also maintain the physical and mechanical properties of the material. This research provides a scientific basis for the development of new environmentally friendly flame-retardant materials and has important theoretical and practical significance.
This study emphasizes the key role of magnesium hydroxide in the design of flame retardant materials and provides new ideas and methods for achieving safer and more environmentally friendly plastic products. With the continuous deepening of magnesium hydroxide modification technology, it is expected to promote technological progress and sustainable development of the flame retardant plastic industry.