In today's chemical and material science fields, the importance of flame retardants is self-evident. They can slow down or prevent the burning of materials when a fire occurs, and they play a vital role in protecting human life and property. This article will explore the composition, classification and selection of flame retardants in depth, and give you a comprehensive understanding of the key knowledge in this professional field.

The composition of flame retardants

Flame retardants have various components, which can be roughly divided into two categories: organic and inorganic according to their chemical properties and structural characteristics. Among organic flame retardants, common ones include organic phosphates, halogen compounds (bromides and chlorine oxides), nitrogen oxides (nitrates), etc., while inorganic flame retardants mainly include inorganic phosphates, metal oxides (iron powder), silicates, carbides, sulfides, borides, phosphides, etc. There are also some special flame retardant ingredients, such as magnesium aluminum spinel, potassium borohydride, sodium borohydride, molybdate, calcium tungstate, etc.

These ingredients have their own characteristics. Some can form a stable heat-insulating layer at high temperatures to prevent heat from transferring into the material; some can capture free radicals produced by combustion to interrupt the combustion chain reaction; and some can release a large amount of non-combustible gas to reduce the oxygen concentration around the material. Through different mechanisms of action, these flame retardant ingredients together form an efficient and stable flame retardant system.

Classification of flame retardants

Flame retardants can be divided into two categories: additive flame retardants and reactive flame retardants according to their addition methods and usage characteristics.

Additive flame retardants are added to polymers by mechanical mixing to make them flame retardant. This type of flame retardant is mainly divided into organic flame retardants and inorganic flame retardants. Organic flame retardants are represented by bromine, phosphorus and nitrogen, nitrogen, red phosphorus and compounds. They can react physically or chemically with polymers to improve the flame retardant properties of polymers. Inorganic flame retardants mainly include antimony trioxide, magnesium hydroxide, aluminum hydroxide, etc. They can form a stable thermal insulation layer at high temperatures to prevent heat from transferring to the inside of the material.

Reactive flame retardants participate in the polymerization reaction as a monomer, so that the polymer itself contains flame retardant ingredients. This type of flame retardant combines with the polymer chain during the polymerization process to form a copolymer with flame retardant properties. Its advantages are that it has little effect on the performance of polymer materials and has long-lasting flame retardancy. Common reactive flame retardants include phosphate esters, vinyl phosphate esters, etc.

How to choose flame retardant

When choosing a flame retardant, you need to fully consider factors such as the product's usage conditions, environmental requirements, and cost. Here are some suggestions for choosing a flame retardant:

1. Choose the right flame retardant according to the environment in which the product is used. For example, for products used in high temperature, high humidity or corrosive environments, it is necessary to choose a flame retardant with good heat resistance, moisture resistance and corrosion resistance.

2. Determine the amount of flame retardant added based on the safety requirements of the product. On the premise of meeting safety requirements, minimize the amount of flame retardant added to reduce costs and reduce the impact on material properties.

3. Fully consider the compatibility of flame retardants with materials. There may be compatibility issues between different flame retardants and different materials, so sufficient testing and evaluation are required to ensure that the flame retardant can effectively improve the flame retardant properties of the material.

4. Pay attention to the environmental performance of flame retardants. When choosing flame retardants, you need to pay attention to whether they meet the requirements of environmental regulations and avoid using flame retardants that are harmful to the environment.

Choosing the right flame retardant is one of the key links to ensure product safety performance. By fully understanding the composition, classification and selection principles of flame retardants, you can better meet product safety requirements and reduce production costs.