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Flame retardant PBT and pet (linear polyester) are two important engineering plastics, which are widely used in electronics, appearance and automotive industry. Its flame retardant products are used in components with high flame retardant requirements. Their flame retardant treatment is as follows:

(1) add bromine flame retardant

Commonly used are decabromodiphenyl ether, brominated polystyrene, brominated epoxy resin, bis (tribromophenoxy) ethane, etc.

For example, adding 10%-15% bromine flame retardant and 3%-5% antimony trioxide can make PBT containing 30% glass fiber reach UL94 V-0 level, and the oxygen index can reach 27%-29%. When using additive flame retardants, attention must be paid to the dispersion in PBT and pet, the easy exudation, and the influence on the gloss and mechanical strength of polyester.

(2) increase brominated phosphate

Tris (dibromophenyl) phosphate is commonly used. Because the same molecule contains BR and P elements, it has halogen phosphorus synergistic effect. Flame retardant efficiency is very high in PBT and pet.

It should be noted that antimony trioxide is often added to the flame retardant treatment for synergistic effect. If the oxygen index test is conducted, the limiting oxygen index will increase. However, in the oxygen rich test environment, Sb and P seem to have an opposite effect. Therefore, UL94 vertical incineration method is the most suitable method to evaluate the flame retardant function of the system.

(3) flame retardant PET is used as flame retardant fiber and fabric

Generally, there are two methods: one is to use hexabromocyclododecane for flame retardant post-treatment of PET fabrics. This kind of fabric can be used as curtain, curtain, wall covering and other indoor decorative fabrics. Due to the post-treatment, the flame retardant is easy to exude, and the fabric feel and flame retardant durability will be inferior.

The other is flame retardant modification by copolymerization. These reactive flame retardant monomers are mainly brominated aromatic compounds, aryl phosphine oxide compounds, brominated aromatic phosphine oxide compounds, etc. As the flame retardant element becomes a part of the molecular center of oligomer, it has the advantages of long flame retardant effect, good hand feel and light resistance.

This article is from Jiangmen Engineering Plastics:http://www.hhaifeng88.cn/