What are the main types of PP flame retardants?

Polypropylene (PP) is one of the most widely used and most productive general-purpose plastics. It has the characteristics of odorless, non-toxic, tasteless, good physical and chemical stability, low density, excellent electrical insulation, and convenient processing. However, the PP raw material itself is a flammable material, the limiting oxygen index is only 17.5, the char formation rate is almost 0, and it is easy to melt and drip. Therefore, the development and use of PP flame retardants are very important. So, what are the main types of PP flame retardants?

PP flame retardants are mainly divided into the following four types:

(1) PP halogen-antimony flame retardant: mainly including decabromodiphenyl ethane, octabromodiphenyl ethane, octabromo ether, tetrabromobisphenol A, etc., and antimony trioxide as a flame retardant synergist.

It has the advantages of small addition amount, high flame retardant efficiency, and good processing performance. However, halogen-containing flame retardant materials will release a large amount of smoke, dioxins and other harmful gases in the event of a fire. Especially since the European Union in 1986 After the restrictions were issued, the prospect of halogen-based flame retardants was cast a shadow.

(2) PP halogen-free flame retardant: masterbatches include XS-PPSH, XS-PPSH-15, XS-PPSH-25, XS-PPSH-35 and XS-PPSH-45, which have high flame retardant performance and thermal stability. Good, good processing performance and other advantages, in line with ROHS requirements, suitable for ordinary PP, talc or glass fiber reinforced PP, black PP and other systems.

It has the advantages of low toxicity, low smoke, low corrosion, no dripping, and small impact on the environment. As people's requirements for environmental protection are getting higher and higher, halogen-free flame retardants have very broad prospects for development.

(3) PP-filled flame retardant: mainly magnesium hydroxide, masterbatches include XS-MHB-3, XS-MHB-5, XS-MHS-7 and XS-MHS-25, etc., which are halogen-free , Non-toxic, environmentally friendly, non-drip, smoke-eliminating and other advantages.

But it needs to be added to more than 50% to have excellent flame retardant effect, which has a great impact on the processing performance and mechanical properties of composite materials, so the filled PP flame retardant can only be used in materials with low performance requirements , Suitable for plastic, rubber, elastomer and other materials;

(4) PP low-halogen flame retardant: masterbatches mainly include XS-PPHM-01, XS-PPHM-02, XS-PPHM-03, XS-PPHM-04, which are suitable for homopolymer, PP The dripping self-extinguishing flame retardant of extrusion, injection molding, filling and other materials can be used in systems such as talc or precipitated barium sulfate. It has the advantages of low dosage, high flame retardant efficiency, no water absorption, no precipitation, resistance to light aging and heat aging, etc. It is a high cost-effective PP flame retardant.

Its flame-retardant principle is based on PP burning and dripping to take away heat, and with the blowing effect of air source, so as to achieve the purpose of flame-retarding. Its addition amount is 1-5 parts, which can pass the glow wire requirement of 750°C. , It can pass the needle flame test of PP products, and can meet the requirements of GWIT775, IEC61249-2-21, etc. when used in PP.