Classification of halogen free flame retardants, flame retardants have the difference between haloge

The difference between halogenated and halogen-free flame retardants is: different ingredients, different harms, and different advantages.

First, the composition is different.

1. Halogen: refers to the flame retardant mixture composed of halogen-containing polymers or halogen-containing flame retardants, mainly antimony trioxide and decabromodiphenyl ether, which is often referred to as bromoantimony grade flame retardants.

2. Halogen-free: It is a high-performance phosphorus and nitrogen organic flame retardant, mainly including triazintrione compounds and triazintriamine compounds.

Second, the harm is different.

1. Halogen: The materials made of halogen-containing flame retardants will produce a large amount of smoke and toxic corrosive hydrogen halide gas when heated, resulting in secondary hazards.

2. Halogen-free: the amount of smoke is small during combustion, and no corrosive and toxic gases are produced.

Third, the advantages are different.

1. Halogen: low cost, good stability, low amount of additives, good compatibility with synthetic resin materials, and can maintain the original physical and chemical properties of flame retardant products.

2. Halogen-free: After special surface treatment, it is easy to disperse in plastic materials, does not precipitate, and has a good flame retardant effect.

Halogenated flame retardants refer to flame retardants containing elements such as CL, BR and F, halogen-free flame retardants include phosphorus series flame retardants, inorganic flame retardants magnesium hydroxide, aluminum hydroxide, zinc borate, etc., in addition to halogen-free flame retardants also include intumescent flame retardants and some special-purpose flame retardants.

Halogenated flame retardant is the most flame retardant product in plastic and rubber materials, mainly because it is an organic flame retardant, chemical inert, good compatibility with plastics, good flame retardant effect, low cost, and many characteristics can not be replaced by other flame retardants.

The European Union's ROSH directive considers that the combustion of halogenated flame retardants such as octabromodiphenyl ether and pentabromodiphenyl ether produces dioxins (carcinogens), which are listed in the list of prohibited uses, and decabromodiphenyl ether is also controversial as a flame retardant that is not recommended for use.

However, most halogenated flame retardants have not been completely banned, and in fact it is difficult to find a product that can truly replace them completely.

As for the harm, sometimes it seems alarmist, there is no restriction on the use of decabromodiphenyl ether flame retardants in China. Its hazards are not necessarily as terrible as the legend says, and the fire retardant is insignificant compared to the natural harm to man.

The components of flame retardants are mainly organic and inorganic, halogenous and non-halogen.

There are many types of flame retardants, which are divided into additive flame retardants and reactive flame retardants according to the method of use.

Additive flame retardants are added to the polymer by mechanical mixing method to make the polymer flame retardant, and the additive flame retardant mainly includes organic flame retardants and inorganic flame retardants, halogenated flame retardants (organochlorides and organic bromide) and non-halogen.

Organic is bromine, phosphorus and nitrogen, nitrogen, red phosphorus and compounds as the representative of some flame retardants, inorganic is mainly antimony trioxide, magnesium hydroxide, aluminum hydroxide, silicon and other flame retardant systems.

Reactive flame retardants participate in the polymerization reaction as a monomer, so the polymer itself contains flame retardant components, which has the advantage of having little impact on the performance of polymer materials and lasting flame retardancy.

How to store flame retardants?

1. Isolated storage: In the same room or in the same area, different concentrations of aluminum hydroxide flame retardants are separated by a certain distance, and the storage method of maintaining space with channels between non-contraindicated materials.

2. Separate storage: In the same building or in the same area, use a partition or wall to separate the aluminum hydroxide flame retardant from the prohibited items.

3. Separate storage: Store in different buildings or in external areas away from all buildings.

At present, the added flame retardants mainly include organic flame retardants and inorganic flame retardants, halogenated flame retardants (organic chlorides and organic bromide) and non-halogen.

Organic is bromine, phosphorus and nitrogen, nitrogen and red phosphorus.

and some flame retardants represented by compounds, inorganic mainly antimony trioxide and magnesium hydroxide.

Aluminum hydroxide, silicon and other flame retardant systems.

Reactive flame retardants are used as monomers to participate in polymerization reactions.

Therefore, the polymer itself contains flame retardant components, and its advantage is that it has less impact on the performance of the polymer material and has long-lasting flame retardancy.

Flame retardant mechanism. The mechanism of action of flame retardants is complex and not yet well understood. It is generally believed that halogens.

The compounds are decomposed when exposed to fire and heat, and the decomposed halogen ions and polymer compounds are generated.

The reaction produces hydrogen halide. The latter is associated with a large number of active hydroxyl free groups proliferated during the combustion of polymer compounds.

ho·) reaction, causing it to decrease its concentration and slow down the rate of combustion until the flame is extinguished.

Among halogens, bromine has a greater flame retardant effect than chlorine. The function of phosphorus-containing flame retardant hollowing agents is that they form metaphosphoric acid when burning, and metaphosphoric acid polymerizes into a very stable poly-bonding state, which becomes a protective layer of plastic and isolates oxygen.

Flame retardants exert their flame retardant effects through several mechanisms, such as endothermy, covering, inhibition of chain reaction, asphyxiation of non-combustible gas, etc. It is pointed out that most flame retardants are used to achieve the purpose of flame retardant through the joint action of several mechanisms.