Halogen free Flame Retardant HFFR

Flame Retardant Definition

Combustion could occur when a substance is heated to its flammable temperature in the presence of oxygen. Flame retardants are generally designed to provide a particular level of resistance to ignition or flame spread. This is achieved by suppressing oxygen availability, building up of char at the surface, inhibiting the combustion reaction within the flame area, or by other mechanisms. Nearly all the present-day commercial FRs and smoke suppressants can be divided into several chemical groups as the table below. Halogen free flame retardants also known as Non-halogenated flame retardants, HFFR,  include phosphorus and nitrogen compounds while do not contain bromine and Chlorine. Also known as HFFR.

Nitrogen flame retardant

Nitrogen-containing flame retardants may act by the release of inert gases like ammonia and nitrogen into the gas phase or by condensation reactions in the solid phase.

table 1 baoxu Nitrogen flame retardant additive

Phosphorus-based flame retardant

PFRs not only react with radicals like BFRs but are also able to act in the condensed phase by enhancing char formation, yielding intumescence (foaming-up) or formation of inorganic glasses. In fact, PFRs are most commonly known as char formers, because during the burning process, they produce phosphoric acids, which, reacting with the substrate, produce a char that acts as a protection of the substrate itself. The most used PFRs are as the table below, their main area of application is in polyamides(PA), polyesters(PET/PBT), polyolefins, and polystyrene (PS) formulations, especially in electrical and electronic insulation components.

table 2 baoxu phosphorus flame retardant additive

Antimony trioxide flame retardant 

Antimony oxide produces vapor-phase radical scavengers while used as a flame retardant. Antimony halides appear to form an important link in the radical scavenging cycle during flame retardancy.

Antimony trioxide(Sb2O3) and pentoxide(Sb2O5)  are used along with halogen flame retardant additives or halogenated polymers due to their synergistic interaction arising from the formation of antimony trihalide

table 3  baoxu antimony flame retardant additive

Silicon flame retardant

organo-layered silicate with the ability to incorporate polymers between the layer structures by intercalation or exfoliation. They do not act as flame retardants on their own, but may, together with other flame retardants, enhance the charring and reduce the heat release of the polymer. The only commercial application to date is the cable sector.

table 4  baoxu silicon flame retardant additive

Sulfonate flame retardant

KSS FR is the potassium salt of a complex of diphenyl sulfone sulfonate and diphenyl sulfone sulfonate. HES FR is specifically designed for the most effective translucent and opaque PC. It is not intended for a transparent PC.

table 5  baoxu sulfonate flame retardant additive

Halogen Free Flame Retardants by Application

table 6  baoxu flame retardant additive by applications

External links

Flame Retardant wikipedia

UL 94 Wikipedia

plastic additive brochure baoxu chemical