How to choose resin for flame-retardant PP of different flame-retardant systems?

Flame-retardant polypropylene has a relatively large choice of resin, and it is conventionally divided into the following categories. But for different flame retardant systems, how should the resin be selected specifically? In other words, what is the priority of choosing resin?

Flame-retardant polypropylene has a relatively large space for choosing resins, and it is conventionally divided into the following categories:

A. Homopolymer high financial index;

B. Homopolymer middle fusion index;

C. Homopolymer low melting index (drawing C or extruding C);

D. Block copolymer high melting index;

E. Melting finger in block copolymerization;

F. Block copolymer low melting index;

G. Random copolymerization (transparent PP)

(1) The priority order and reason analysis of flame retardant PP resin selection for intumescent flame retardant system:

  For the above types, if an intumescent flame retardant system is used (B or C is the preferred solution), the specific priority order is: homopolymer low melt index> homopolymer middle melt index> homopolymer middle melt index> homopolymer high melt index >Block copolymerization high melt index>Block copolymerization middle melt index>Block copolymerization low melt index.

   Reason analysis: the content of propylene in the copolymerization will affect the carbon formation of the carbon formation system. In a homopolymerization system, the larger the molecular weight, the easier it is to form carbon.

(2) The priority order and reason analysis of selecting resin for flame-retardant PP for high-efficiency flame-retardant system:

  For the above types, if an efficient flame retardant system is used (D is the preferred solution), the specific priority order is: homopolymer high melt index> homopolymer middle melt index> homopolymer low melt index> block copolymer high melt index> embedded Melt index in segment copolymerization>low melt index in block copolymerization;

   Reason analysis: the ethylene component in the copolymer resin will cause partial failure of the high-efficiency flame retardant. In the same type, the higher the melting index, the easier it is to drip during burning, and the easier it is to flame retardant.

(3) The amount of flame retardant required for the same index of resin in the production of flame retardant PP will also be different

   Take the block middle melt index as an example. The author has proved through a lot of experiments that the flame retardant of the same index resin, SK resin, is the smallest when producing flame-retardant polypropylene, followed by Taiwan Chemical, and the worst is the domestic coal chemical industry. Produced.

(4) The choice of resin has a great impact on the cost-effectiveness of high-efficiency flame-retardant system flame-retardant PP

In other words, when using high-efficiency flame retardants to produce flame-retardant polypropylene, the choice of resin plays a very critical role in the cost-effectiveness of the entire formulation.