Magnesium hydroxide-based halogen-free flame-retardant polyester composites: a double breakthrough in environmental protection and performance

With the improvement of environmental awareness, the development of environmentally friendly flame retardant materials has become an important topic in the field of materials science. Magnesium hydroxide (Mg(OH)2), with its halogen-free, low-smoke and non-toxic properties, is considered to have the potential to replace traditional halogen-containing flame retardants. In particular, its application in polyester materials, such as polyethylene terephthalate (PET), shows great application prospects.

Preparation technology

1. Blending extrusion method: Premix magnesium hydroxide and polyester resin through a high-speed mixer, then melt blend at a specific temperature using a twin-screw extruder, and finally granulate to obtain a composite material. This method is popular because of its simple operation.

2. In-situ polymerization method: Magnesium hydroxide is directly added during the polyester synthesis process to make it evenly dispersed in the polymerization reaction to form a composite material. This method helps to improve the dispersion effect and interface compatibility.

3. Surface modification: In order to enhance the bonding strength of magnesium hydroxide and polyester matrix, coupling agents, silanes, fatty acids, etc. are usually used for surface modification to improve the overall performance of the composite material.

Performance evaluation

1. Flame retardant performance: The flame retardant effect of the composite material is comprehensively evaluated through oxygen index test (LOI), vertical burning test (UL-94), cone calorimeter and other methods.

2. Mechanical properties: The tensile strength, elongation at break, flexural strength and other properties of the composite material are tested to evaluate the effect of magnesium hydroxide addition on the mechanical properties of the material.

3. Thermal stability: The thermal stability and thermal decomposition behavior of the composite material are studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).

4. Microstructure: The microstructure of the composite material is observed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and other techniques to understand the dispersion of magnesium hydroxide in the matrix.

5. Smoke density and toxicity: The smoke generation and toxic gas emissions during material combustion are evaluated to ensure the safety of halogen-free flame retardant materials.

Application prospects Studies have shown that the addition of an appropriate amount of magnesium hydroxide can not only significantly improve the flame retardant properties of polyester composites, but also maintain or improve their mechanical properties. This type of composite material has wide application potential in the fields of electrical and electronic equipment housings, building interior materials, textiles, automotive interior parts, etc., especially in places with strict requirements for environmental protection and safety.

The development of magnesium hydroxide-based halogen-free flame-retardant polyester composite materials not only meets the flame retardant needs of materials, but also responds to the society's pursuit of environmental protection and sustainable development. Research in this field undoubtedly provides new directions and possibilities for the future development of flame retardant materials.