About Phyrolex

Phyrolex is probably a big step forward in fire protection. It is covered by UK Patent. GB1717130.7. This is a substance patent not an application patent.

It comes in two forms: liquids that can be used to react phenolic resins, create paints and films and low viscosity soak in treatments for timber and High viscosity liquids, available at 100% NVC or as aqueous solutions that are inherently intumescent Here. The principle behind Phyrolex is to take the functional components of a conventional intumescent formulation and react these into a polymeric molecule. The Phyrolex flame retardants are a reaction product. What they are not is a mixture of separate compounds.

Thus the Phyrolex LFR’s are polymeric compounds that combine the functions (but not the structure) of the catalyst (ammonium polyphosphate), carbonific (pentaerythritol) and spumescent (melamine) that exist in conventional intumescent mixtures. After an extended development period, you may well have heard the principle expounded before.

Phyrolex Flame Retardants :-

  • Are more efficient than other flame retardants
  • Produce less smoke than other flame retardants
  • Are lighter than other flame retardants
  • Contain no toxic components
  • Are halogen free
  • Have the widest range of applications
  • Are biodegradable
  • Are based on sustainable raw materials

How is Phyrolex different?

Phyrolex is inherently intumescent. This means that there is no longer the requirement to blend together the components of an intumescent system. This gives the advantage of allowing the use of an intumescent system in resins that traditionally have been protected by either halogens and gas phase synergists or other endothermic systems.

In a conventional intumescent mixture a number of intermediate reactions must occur before the separate components can react with each other. The major effect of using a system that is inherently intumescent is that these reactions have already taken place and therefore fire protection takes place at a lower temperature. If the protection starts at a lower temperature then polymers and substrates that would have otherwise decomposed to flammable fractions are more effectively protected.

The Phyrolex flame retardants activate with little or no smoke emission and if the polymers and substrates are prevented from decomposition to flammable fractions then the overall smoke yield is lower. Phyrolex flame retardants have a higher char yield than intumescent mixtures. If pyrolitic decomposition is reduced then the ability of the non-flammable char yield to protect underlying substrates from the flame or a heat front is greater.

In common with conventional intumescent mixtures the decomposition of Phyrolex flame retardants is endothermic throughout and the final char is the same mixture of finely divided amorphous carbon in condensed phosphoric acids.

The system is halogen free and therefore little additional effect can be expected from “gas phase” synergists.




Which Phyrolex do I want?

If you’re looking to create a flame retardant coating then you probably want to use Phyrolex PCP. It is a liquid provided at 80% solids that may be used to create water based two pack flame retardant intumescent clear varnishes and paints for protective coatings for structural steel, timber panels and doors as well as all thermoset and thermoplastic resins.

If you’re looking to protect composites like polyesters or epoxy prepregs then we generally recommend you use one of our two pack coatings:

  • The coating requires no modification to the resin system or production process
  • The inherent physical properties of the resin system are maintained
  • The fact that the coating is on the surface means that the smoke production is lower than any flame retardant incorporated into the resin structure
  • By using one of our topcoats the whole system can be suitable for external applications with no UV or moisture sensitivity

If however you wish to incorporate your flame retardant into the resin matrix then you will be wanting to use Phyrolex LFR. Phyrolex LFR is an intumescent liquid that may be mixed into the base resins such as polyesters, epoxies, polyurethanes, and polysiloxanes to render them fire retardant or fire protective as composites, coatings, elastomers or foams.

The advantage of using Phyrolex in these resin systems is that the smoke production is so significantly reduced that it should allow the use of these materials in areas where previously they have been off limits, for example using polyester resins in underground trains.

If you are wanting to create latent curing phenolic resin systems then you will be wanting to use one of our Phyrolex Partial phosphate ester resin systems. These come in a range of viscosities and water contents, they can be fine tuned to your individual cure requirements.

See Phyrolex FAQ