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Flame retardant effect of polyurethane flame retardant
2017-11-15 15:44:22
Flame retardant effect of polyurethane flame retardant
The combustion of the polymer is a very complicated thermal oxidation, has the characteristics of cold smoke or burning flame. The general process of combustion is in constant heating external heat source, the first polymer free radical chain degradation reaction with oxygen in the air, produce volatile combustibles, certain concentration and temperature of the material will be on fire, burning out a part of the heat supply is the degradation of polymer, further intensified its degradation, produce more of the combustible gas, flame in a very short period of time will spread rapidly and cause a fire.
Polyurethane flame retardant is a kind of additives that can prevent polyurethane from igniting or inhibiting flame propagation. According to the flame retardant effect of polyurethane flame retardant, it can be divided into two types: additive type and reactive type. Additive flame retardants are added to plastics in the process of plastics, mostly used in thermoplastics. Reactive flame retardants are chemically bonded to polymer chains in the process of polymer synthesis. They are mostly used for thermosetting plastics, and some reactive flame retardants can also be used as additive flame retardants.
According to the chemical structure, flame retardant can be divided into inorganic and organic two categories, in these compounds contain halogen and phosphorus, and some contain antimony, boron, aluminum and other elements.
The flame retardant effect of polyurethane flame retardant is that it can prevent or inhibit the physical or chemical changes in the process of burning of polyurethane. Specifically, these functions are reflected in the following aspects:
Polyurethane flame retardant effect (1) the endothermic effect and its role is to enable the polymer material temperature rise is difficult, for example, borax has 10 crystal water molecules, the release of crystal water to capture 141.8kJ/mol heat due to the temperature rise of the endothermic material was inhibited, resulting in flame retardant effect. The flame retardant effect of hydrated alumina is also due to the endothermic effect of heat dehydration. In addition, some of the droplets which are often produced by pyrolysis of thermoplastic polymers can also play a certain role in flame retardancy because they can remove the reaction heat from the combustion zone.
Polyurethane flame retardant effect (2) covering effect and its role is to generate stable layer at higher temperatures, or decomposition of foam material, the surface coverage in the polymer materials, the combustion heat generated inside the material is difficult to spread, the combustible gas generated by the heat to high polymer material. The difficult to escape, and the role of isolated air on the material, thereby inhibiting material cracking, flame retardancy effect. Such as phosphate ester and fire retardant foam coating can play a role in this mechanism.
Triphenyl Phosphate (TPP)
Flame retardant TPP has many advantages, such as excellent transparency, softness, bacterial resistance, and water proof, grease-proof, good electric insulation, as well as good compatibility. Flame retardant TPP is mainly used as the flame-retardant plasticizer for cellulose resin, vinyl resin, natural rubber and synthetic rubber. And it may also be used as the flame-retardant plasticizer for glyceryl triacetate thin ester and film, rigid polyurethane foam, phenolic aldehyde resin, and PPO, etc.
Flame retardant TPP is a kind of halogen-free environment-friendly flame retardant with phosphorus element. Most of the products in the market are self-colored flaky crystal, our product is self-colored crystalline powder, and is more soluble in organic solvents. TPP is not soluble in water, but soluble in benzene, chloroform, ether and acetone, and slightly soluble in Z alcohol. Flame retardant TPP is nonflammable with slight aromatic odor and slight deliquescence. The fusion point is about 50 ℃, and fast melts to hoop-shape when heated. The lubricate effect is excellent, and it is often used as the flame retardant plasticize lubricant. What is more, it is used as the flame retardant for many plastics and resins, such as phenolic aldehyde resin, epoxy resin and so on.
Polyurethane flame retardant effect (3) dilution effect of such substances can produce a large number of non flammable gas in thermal decomposition, so that the oxygen polymer materials produced by the combustible gas and air is diluted and not up to the concentration range of combustible, so as to prevent the polymer materials burn. CO2, NH3, HCl and H2O can be used as diluent gas. This nonflammable gas can be produced when heated by amines such as amines, amines, amines, and carbonates.
Flame retardant effect of polyurethane flame retardant (4) transfer effect is to change the mode of thermal decomposition of polymer materials, thereby inhibiting the production of combustible gas. For example, acid or alkali causes cellulose to dehydrate and decomposes into carbon and water, because it does not produce combustible gas and can not ignite and burn. Chlorinated amine, phosphate amine, phosphate and so on can decompose to produce this kind of substance, the catalytic material is fused and carbonized, so as to achieve the purpose of flame retardant.
Polyurethane flame retardant effect (5) inhibition (capture free radicals), polymer combustion mainly is a free radical chain reaction, some substances can capture combustion reaction intermediates, HO? H? And? O?, HOO?, inhibit free radical chain reaction, the combustion speed reduced until the flame is extinguished. Commonly used bromine, chlorine and other organic halogen compounds have this inhibitory effect.
Flame retardant effect of polyurethane flame retardant (6) reinforcing effect (synergistic effect), some materials, if single use, no flame retardant effect or flame retardant effect is not big, a variety of materials can be used to enhance the effect of flame retardant. Three oxidation of two antimony with halogen compounds, is the most typical example. The result is that not only the flame retardant efficiency can be improved, but also the amount of flame retardant can be reduced.
The flame retardancy of the material is realized by flame retardant, condensed phase flame retardant, interrupted heat exchange, flame retardant and other mechanisms. Inhibition of promoting combustion reaction chain growth ability of free radicals is a flame retardant function of gas phase flame retardant; delay or prevent the polymer thermal decomposition flame retardant effect of condensed phase flame in solid phase; flame retardant polymer combustion heat generated away due to the flame retardant belongs to the class of physical interruption of heat exchanger.
But burning and flame retardant are very complex processes, involving many influencing factors and restricting factors. It is difficult to strictly classify the flame retardant mechanism of a flame retardant system into a certain kind of flame retardant system. In fact, many flame retardant systems act at the same time with several flame retardant mechanisms.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
The combustion of the polymer is a very complicated thermal oxidation, has the characteristics of cold smoke or burning flame. The general process of combustion is in constant heating external heat source, the first polymer free radical chain degradation reaction with oxygen in the air, produce volatile combustibles, certain concentration and temperature of the material will be on fire, burning out a part of the heat supply is the degradation of polymer, further intensified its degradation, produce more of the combustible gas, flame in a very short period of time will spread rapidly and cause a fire.
Polyurethane flame retardant is a kind of additives that can prevent polyurethane from igniting or inhibiting flame propagation. According to the flame retardant effect of polyurethane flame retardant, it can be divided into two types: additive type and reactive type. Additive flame retardants are added to plastics in the process of plastics, mostly used in thermoplastics. Reactive flame retardants are chemically bonded to polymer chains in the process of polymer synthesis. They are mostly used for thermosetting plastics, and some reactive flame retardants can also be used as additive flame retardants.
According to the chemical structure, flame retardant can be divided into inorganic and organic two categories, in these compounds contain halogen and phosphorus, and some contain antimony, boron, aluminum and other elements.
The flame retardant effect of polyurethane flame retardant is that it can prevent or inhibit the physical or chemical changes in the process of burning of polyurethane. Specifically, these functions are reflected in the following aspects:
Polyurethane flame retardant effect (1) the endothermic effect and its role is to enable the polymer material temperature rise is difficult, for example, borax has 10 crystal water molecules, the release of crystal water to capture 141.8kJ/mol heat due to the temperature rise of the endothermic material was inhibited, resulting in flame retardant effect. The flame retardant effect of hydrated alumina is also due to the endothermic effect of heat dehydration. In addition, some of the droplets which are often produced by pyrolysis of thermoplastic polymers can also play a certain role in flame retardancy because they can remove the reaction heat from the combustion zone.
Polyurethane flame retardant effect (2) covering effect and its role is to generate stable layer at higher temperatures, or decomposition of foam material, the surface coverage in the polymer materials, the combustion heat generated inside the material is difficult to spread, the combustible gas generated by the heat to high polymer material. The difficult to escape, and the role of isolated air on the material, thereby inhibiting material cracking, flame retardancy effect. Such as phosphate ester and fire retardant foam coating can play a role in this mechanism.
Triphenyl Phosphate (TPP)
Flame retardant TPP has many advantages, such as excellent transparency, softness, bacterial resistance, and water proof, grease-proof, good electric insulation, as well as good compatibility. Flame retardant TPP is mainly used as the flame-retardant plasticizer for cellulose resin, vinyl resin, natural rubber and synthetic rubber. And it may also be used as the flame-retardant plasticizer for glyceryl triacetate thin ester and film, rigid polyurethane foam, phenolic aldehyde resin, and PPO, etc.
Flame retardant TPP is a kind of halogen-free environment-friendly flame retardant with phosphorus element. Most of the products in the market are self-colored flaky crystal, our product is self-colored crystalline powder, and is more soluble in organic solvents. TPP is not soluble in water, but soluble in benzene, chloroform, ether and acetone, and slightly soluble in Z alcohol. Flame retardant TPP is nonflammable with slight aromatic odor and slight deliquescence. The fusion point is about 50 ℃, and fast melts to hoop-shape when heated. The lubricate effect is excellent, and it is often used as the flame retardant plasticize lubricant. What is more, it is used as the flame retardant for many plastics and resins, such as phenolic aldehyde resin, epoxy resin and so on.
Polyurethane flame retardant effect (3) dilution effect of such substances can produce a large number of non flammable gas in thermal decomposition, so that the oxygen polymer materials produced by the combustible gas and air is diluted and not up to the concentration range of combustible, so as to prevent the polymer materials burn. CO2, NH3, HCl and H2O can be used as diluent gas. This nonflammable gas can be produced when heated by amines such as amines, amines, amines, and carbonates.
Flame retardant effect of polyurethane flame retardant (4) transfer effect is to change the mode of thermal decomposition of polymer materials, thereby inhibiting the production of combustible gas. For example, acid or alkali causes cellulose to dehydrate and decomposes into carbon and water, because it does not produce combustible gas and can not ignite and burn. Chlorinated amine, phosphate amine, phosphate and so on can decompose to produce this kind of substance, the catalytic material is fused and carbonized, so as to achieve the purpose of flame retardant.
Polyurethane flame retardant effect (5) inhibition (capture free radicals), polymer combustion mainly is a free radical chain reaction, some substances can capture combustion reaction intermediates, HO? H? And? O?, HOO?, inhibit free radical chain reaction, the combustion speed reduced until the flame is extinguished. Commonly used bromine, chlorine and other organic halogen compounds have this inhibitory effect.
Flame retardant effect of polyurethane flame retardant (6) reinforcing effect (synergistic effect), some materials, if single use, no flame retardant effect or flame retardant effect is not big, a variety of materials can be used to enhance the effect of flame retardant. Three oxidation of two antimony with halogen compounds, is the most typical example. The result is that not only the flame retardant efficiency can be improved, but also the amount of flame retardant can be reduced.
The flame retardancy of the material is realized by flame retardant, condensed phase flame retardant, interrupted heat exchange, flame retardant and other mechanisms. Inhibition of promoting combustion reaction chain growth ability of free radicals is a flame retardant function of gas phase flame retardant; delay or prevent the polymer thermal decomposition flame retardant effect of condensed phase flame in solid phase; flame retardant polymer combustion heat generated away due to the flame retardant belongs to the class of physical interruption of heat exchanger.
But burning and flame retardant are very complex processes, involving many influencing factors and restricting factors. It is difficult to strictly classify the flame retardant mechanism of a flame retardant system into a certain kind of flame retardant system. In fact, many flame retardant systems act at the same time with several flame retardant mechanisms.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
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