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Inorganic flame retardant for polyolefins
2017-11-15 15:44:27
Inorganic flame retardant for polyolefins
Inorganic flame retardant polyolefin include aluminum hydroxide, magnesium hydroxide, red phosphorus flame retardant, expanded graphite. Aluminum hydroxide and magnesium hydroxide are the main varieties of inorganic inhibitors, which have the characteristics of non-toxic and low smoke. Because they absorb a lot of heat decomposition combustion zone heat, combustion zone temperature is reduced to below the critical temperature of combustion combustion self extinguishing: most metal oxides generated after the decomposition of high melting point, good thermal stability, covered on the combustion of solid surface barrier heat conduction and heat radiation from and to prevent fire. At the same time, a large amount of water vapor is decomposed, which can dilute the combustible gas, and also play a role of flame retardant.
Polyolefin inorganic flame retardant in hydrated alumina has good thermal stability, heated at 300 DEG C 2H can be transformed into AlO (OH), harmful gases can be generated after contact with the flame, and the acid gas release and polymer pyrolysis, less smoke, cheap and other advantages, so it is an important variety of inorganic flame retardant in polyolefin. Hydrated alumina releases the chemically bound water, absorbs the heat and reduces the combustion temperature. In the play the role of flame retardance, two main crystallization water play a role, in addition, dehydration is the product of activated alumina, can promote some polymer in the combustion of fused ring carbonization, therefore it has condensed phase flame retardant effect. According to this mechanism, hydrated alumina should be used as a flame retardant, and the amount of addition should be larger.
The main varieties of flame retardant magnesium hydroxide, is a kind of flame retardant is being developed at home and abroad in recent years. It starts at about 340 DEG C for endothermic decomposition reaction of Magnesium Oxide, under the temperature of 423 DEG C lost weight reached the maximum value, the termination of 490 C decomposition reaction. From the calorimetric method, the reaction absorbs a large amount of heat energy (44.8KJ/mol), and the generated water also absorbs a large amount of heat energy, reduces the temperature and achieves flame retardancy. The thermal stability of the magnesium hydroxide and smoke suppression ability than hydrated alumina, but because magnesium hydroxide surface polarity, and organic matter poor compatibility, so after surface treatment can be used as effective flame retardant. In addition, the thermal decomposition temperature of the polymer is high, which is suitable for the flame retardant of the thermosetting polymers with higher decomposition temperature.
At high temperature, the embedded layer in the expandable graphite is easy to decompose under heating, and the resulting gas expands the layer spacing of graphite to several times to several hundred times. When the expandable graphite is mixed with the polymer, the tough carbon layer can be formed on the surface of the polymer under the action of flame, so as to play a role of flame retardant.
Borate flame retardants include borax, boric acid and zinc borate. Zinc borate is mainly used at present. In 300 C zinc borate began releasing crystal water in halogen compounds under the action of boron halide, generating zinc halide, suppressing and capture free hydroxyl, prevent combustion of chain reaction; while the formation of solid layer, isolating the ambient oxygen, prevent the flame and smoke suppression function. Zinc borate can be used alone or in combination with other flame retardants.
Triphenyl Phosphate (TPP)
Retardants tpp quality standards:
Appearance: white flaky crystal
Content : ≥ 99%;
Acid value (mgKOH / g): ≤ 0.1;
Free phenol : ≤ 0.1%;
Freezing point : ≥ 47.0 ℃
Chromaticity (APHA): ≤ 60;
Moisture : ≤ 0.1%
Density (50 ℃, g/cm3) :1.185-1 .202
Retardants tpp Packing: NW 25KG / composite paper ( lined with black plastic bags ) , a small cabinet loaded 12.5 tons .
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.
At present, the main products are fine grained zinc borate, heat resistant zinc borate, anhydrous zinc borate and high water zinc borate. Aluminium oxalate is a crystalline substance derived from aluminium hydroxide with low alkali content. When the polymers containing aluminium oxalate are burned, H20, CO and CO2 are released, but no corrosive gas is produced. Aluminum oxalate can also reduce the smoke density and smoke generation rate. Because the alkali content of aluminium oxalate is low, the electrical properties of the material are not affected by the flame retardant wires and cables.
5 kinds of flame retardants based on ZnS have been developed, of which 4 are used for hard PVC, and the other for soft PVC, polyolefin diameter and nylon. This kind of flame retardant can improve the aging resistance of the material, and has good compatibility with glass fiber and improve the thermal stability of polyolefin.
Phosphorus containing flame retardant is also a free radical scavenger. It is found by mass spectrometry that any phosphorus containing compound has PO formation in the combustion of polymers. It can combine with the hydrogen atom in the flame region to inhibit the flame. In addition, flame retardant in flame retardant in the process of water, one can reduce the temperature of the condensed phase, on the other hand can dilute the concentration of combustible gas phase, so as to better play the role of flame retardant.
Phosphorus and phosphorus compounds have long been used as flame retardant, flame retardant mechanism of its research was initially found earlier, combustion of phosphorus containing flame retardant materials will generate a lot of coke, and reduces the production of combustible volatile substances, burning flame retardant materials heat loss is greatly reduced, but the smoke density of flame retardant materials when burning than non flame retardant increased. Some flame retardant mechanisms are proposed according to the above facts. The phosphorus compounds in different reaction zone can be divided into the flame retardant effect of condensed phase flame retardant mechanism and vapor phase, organic phosphorus flame retardant in condensed phase play the effect of flame retardant, the flame retardant mechanism are as follows:
When burning, the phosphorus compound decomposes into phosphoric acid non combustible liquid membrane, its boiling point can reach 300 degrees centigrade. At the same time, the phosphoric acid is further dehydrated to form partial phosphoric acid, and the partial phosphoric acid is further polymerized to form poly phosphoric acid. In this process, not only the covering layer is made of phosphoric acid to produce to the covering effect, but also due to the formation of polymetaphosphate is strong, is dehydrating agent is very strong, so that the polymer dehydration and carbonization, change the combustion process of polymer model and the formation of carbon film on the surface of the air, and thus play a stronger retarding effect.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
Inorganic flame retardant polyolefin include aluminum hydroxide, magnesium hydroxide, red phosphorus flame retardant, expanded graphite. Aluminum hydroxide and magnesium hydroxide are the main varieties of inorganic inhibitors, which have the characteristics of non-toxic and low smoke. Because they absorb a lot of heat decomposition combustion zone heat, combustion zone temperature is reduced to below the critical temperature of combustion combustion self extinguishing: most metal oxides generated after the decomposition of high melting point, good thermal stability, covered on the combustion of solid surface barrier heat conduction and heat radiation from and to prevent fire. At the same time, a large amount of water vapor is decomposed, which can dilute the combustible gas, and also play a role of flame retardant.
Polyolefin inorganic flame retardant in hydrated alumina has good thermal stability, heated at 300 DEG C 2H can be transformed into AlO (OH), harmful gases can be generated after contact with the flame, and the acid gas release and polymer pyrolysis, less smoke, cheap and other advantages, so it is an important variety of inorganic flame retardant in polyolefin. Hydrated alumina releases the chemically bound water, absorbs the heat and reduces the combustion temperature. In the play the role of flame retardance, two main crystallization water play a role, in addition, dehydration is the product of activated alumina, can promote some polymer in the combustion of fused ring carbonization, therefore it has condensed phase flame retardant effect. According to this mechanism, hydrated alumina should be used as a flame retardant, and the amount of addition should be larger.
The main varieties of flame retardant magnesium hydroxide, is a kind of flame retardant is being developed at home and abroad in recent years. It starts at about 340 DEG C for endothermic decomposition reaction of Magnesium Oxide, under the temperature of 423 DEG C lost weight reached the maximum value, the termination of 490 C decomposition reaction. From the calorimetric method, the reaction absorbs a large amount of heat energy (44.8KJ/mol), and the generated water also absorbs a large amount of heat energy, reduces the temperature and achieves flame retardancy. The thermal stability of the magnesium hydroxide and smoke suppression ability than hydrated alumina, but because magnesium hydroxide surface polarity, and organic matter poor compatibility, so after surface treatment can be used as effective flame retardant. In addition, the thermal decomposition temperature of the polymer is high, which is suitable for the flame retardant of the thermosetting polymers with higher decomposition temperature.
At high temperature, the embedded layer in the expandable graphite is easy to decompose under heating, and the resulting gas expands the layer spacing of graphite to several times to several hundred times. When the expandable graphite is mixed with the polymer, the tough carbon layer can be formed on the surface of the polymer under the action of flame, so as to play a role of flame retardant.
Borate flame retardants include borax, boric acid and zinc borate. Zinc borate is mainly used at present. In 300 C zinc borate began releasing crystal water in halogen compounds under the action of boron halide, generating zinc halide, suppressing and capture free hydroxyl, prevent combustion of chain reaction; while the formation of solid layer, isolating the ambient oxygen, prevent the flame and smoke suppression function. Zinc borate can be used alone or in combination with other flame retardants.
Triphenyl Phosphate (TPP)
Retardants tpp quality standards:
Appearance: white flaky crystal
Content : ≥ 99%;
Acid value (mgKOH / g): ≤ 0.1;
Free phenol : ≤ 0.1%;
Freezing point : ≥ 47.0 ℃
Chromaticity (APHA): ≤ 60;
Moisture : ≤ 0.1%
Density (50 ℃, g/cm3) :1.185-1 .202
Retardants tpp Packing: NW 25KG / composite paper ( lined with black plastic bags ) , a small cabinet loaded 12.5 tons .
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.
At present, the main products are fine grained zinc borate, heat resistant zinc borate, anhydrous zinc borate and high water zinc borate. Aluminium oxalate is a crystalline substance derived from aluminium hydroxide with low alkali content. When the polymers containing aluminium oxalate are burned, H20, CO and CO2 are released, but no corrosive gas is produced. Aluminum oxalate can also reduce the smoke density and smoke generation rate. Because the alkali content of aluminium oxalate is low, the electrical properties of the material are not affected by the flame retardant wires and cables.
5 kinds of flame retardants based on ZnS have been developed, of which 4 are used for hard PVC, and the other for soft PVC, polyolefin diameter and nylon. This kind of flame retardant can improve the aging resistance of the material, and has good compatibility with glass fiber and improve the thermal stability of polyolefin.
Phosphorus containing flame retardant is also a free radical scavenger. It is found by mass spectrometry that any phosphorus containing compound has PO formation in the combustion of polymers. It can combine with the hydrogen atom in the flame region to inhibit the flame. In addition, flame retardant in flame retardant in the process of water, one can reduce the temperature of the condensed phase, on the other hand can dilute the concentration of combustible gas phase, so as to better play the role of flame retardant.
Phosphorus and phosphorus compounds have long been used as flame retardant, flame retardant mechanism of its research was initially found earlier, combustion of phosphorus containing flame retardant materials will generate a lot of coke, and reduces the production of combustible volatile substances, burning flame retardant materials heat loss is greatly reduced, but the smoke density of flame retardant materials when burning than non flame retardant increased. Some flame retardant mechanisms are proposed according to the above facts. The phosphorus compounds in different reaction zone can be divided into the flame retardant effect of condensed phase flame retardant mechanism and vapor phase, organic phosphorus flame retardant in condensed phase play the effect of flame retardant, the flame retardant mechanism are as follows:
When burning, the phosphorus compound decomposes into phosphoric acid non combustible liquid membrane, its boiling point can reach 300 degrees centigrade. At the same time, the phosphoric acid is further dehydrated to form partial phosphoric acid, and the partial phosphoric acid is further polymerized to form poly phosphoric acid. In this process, not only the covering layer is made of phosphoric acid to produce to the covering effect, but also due to the formation of polymetaphosphate is strong, is dehydrating agent is very strong, so that the polymer dehydration and carbonization, change the combustion process of polymer model and the formation of carbon film on the surface of the air, and thus play a stronger retarding effect.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
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