Basic knowledge of flame retardant polypropylene
Basic knowledge of flame retardant polypropylene
(1) Halogen-antimony system, i.e. vapor flame retardant mechanism. Commonly used halogen flame retardants are decabromodiphenyl ether, hexabromocyclododecane, octabromo ether, tetrabromobisphenol A, etc. With antimony trioxide as flame retardant synergist, they have the characteristics of low addition and good flame retardant effect. However, halogen flame retardants have been criticized by green environmental organizations, so that in some countries they are restricted and banned. However, the United States, Japan and other countries still allow the use of halogen flame retardants, so as a developing country in China, the life of halogen flame retardants at least 10 years.
(2) PP was treated with Bromoalkyl phosphate. This kind of flame retardant has the synergistic effect of P Br, which makes the flame retardant effect remarkable. At the same time, it can improve the rheological and processing properties of PP, and has little effect on the physical and mechanical properties of PP.
(3) In the past decade, the intumescent flame retardant initiated by Professor Camino, Turin University, Italy, has played a great role in PP flame retardant technology. This kind of P N series flame retardant has high efficiency, high thermal and light stability, low toxicity, low smoke and low corrosion. It has little impact on processing and mechanical properties and does not cause environmental pollution. In PP, only 2530 copies can reach UL94V 0 level. The production of intumescent flame retardant products has just been reported in China.
(4) Polypropylene flame retardant by graft copolymer of pentabromobenzyl acrylate and ethylene propylene terpolymer. This kind of flame retardant PP has high impact strength and can be used as engineering plastics in some occasions.
Inorganic filler flame retardant polypropylene so-called inorganic filler refers to aluminium hydroxide and magnesium hydroxide, they have the function of flame retardant and smoke suppression. However, to achieve the desired results, micronization and surface treatment are key technologies, which are applied to different plastics. It is necessary to carefully select suitable surfactants to make them compatible with plastics and disperse them evenly in plastics without greatly affecting the mechanical properties of plastics. Because ATH and magnesium hydroxide can play the role of flame retardant and smoke suppression in different temperature range, the combination of ATH and magnesium hydroxide can make the plastics play a sustained flame retardant effect in a wide temperature range. It should be emphasized here that in order to achieve better flame retardant effect and appropriate mechanical properties, two-step feeding method should be adopted in the mixing process of adding magnesium hydroxide to treat PP, so that better results can be obtained than one feeding.
