Flame retardant additives for Wuhan Handern Nylon
DATE：2020/6/4 8:32:03 / READ： / SOURCE：This station
Flame retardant additives for Wuhan Handern Nylon
1. Halogen-containing additivesThe main function of halogenated flame retardants is to delay or prevent the combustion of the polymer in the gas phase. When the flame retardants are heated, they liberate free radicals, which extract hydrogen atoms from the polymer substrate to generate hydrogen halide molecules and add them to the gas phase. In the gas phase, the hydrogen halide can react with the hydroxyl radical to achieve flame retardant and fire prevention. On the other hand, the thermal degradation products of the polymer change, easily forming unsaturated hydrocarbons, or even carbonized residues, thereby improving the flame retardant effect of the condensed phase. Halogen-based flame retardants are very effective for both unreinforced and reinforced nylon. It can be used together with synergistic metal oxides, metal salts, phosphorus-containing compounds, or char-forming agents. However, the flame retardants can also cause the nylon chain to crack into combustible monomers. Or similar things initiated or catalyzed by hydrogen halide (HX).
The chlorinated flame retardant is mainly a binary addition product of hexachlorocyclodiene and cyclooctadiene produced by the Tyuls Adell reaction of bis(hexachlorocyclopentadiene)cyclooctane, which is in nylon Most commonly used. The commonly used trade names of chlorinated flame retardants are: Dechlorane 515 or Dechlorane Plus flame retardant nylon. The components mainly include 15% to 30% chloride additives and 4% to 15% metal oxide synergists, synergists Including antimony trioxide, iron oxide, zinc oxide and zinc borate, iron oxide is the most effective in PA6. Black FeO and yellow hydrated iron oxide are also effective. 12% Dechlorane Plus and 3% iron oxide can make the material reach the V-0 level (1.6mm) in the UL-94 test.
Synergist Flnmtards (Nano,) can be used as a substitute for antimony trioxide. This is a white inorganic powder with a relative density of 3.9 and a particle size of 2pm. Not easy to drip. 79% PA66 with 15% Dechlorane i and 4% Flamtards and 2% zinc methionate can reach UL94V-0 level.
PA6 is more difficult to flame retardant than PA66. Tests with different proportions of Flamtards935 and zinc borate, which can reach V-0 at a thickness of 1.6mm, can be considered as a successful flame retardant. The best formula is 79% PA6, 15%
Dechlorane, 4% FlamtardsSi and 2% zinc borate.
The brominated flame retardant is Firemaster935, with a bromine content of 16%, and a softening temperature at 210-225°C. For unreinforced PA6, to achieve UL94 V0 level (1.6m), the minimum addition of Firemaster935 is 16%, and 4% of TiO2 is added. In 33%6 glass fiber reinforced resin, 14% Firemaster935 And 3.5% antimony trioxide can reach UL94V-0 level.
Another brominated flame retardant is FR1025, which has a high content and high thermal stability. Measured by LO1 value, when the ratio of FR1025 to antimony trioxide is 311, the flame retardant effect is the best. Thermogravimetric analysis of PA66 containing FR1025 and antimony trioxide shows that: FR1025 reacts with antimony trioxide in the condensed phase, thus reducing the decomposition temperature. Halogen flame retardants are one of the most important flame retardant systems in nylon. They have excellent flame retardancy, processability and compatibility, good weatherability, chemical stability and electrical properties. Lack of stability against UV light and easy to frost on the surface, while emitting flame retardant polymers, emit toxic smoke and gas. More and more industries and departments have begun to restrict or stop the use of halogenated flame retardants.
Author：admin