Can I use Phyrolex LFR in Thermoplastics?
- Yes, But with some modifications if it is master batched. While Phyrolex products can be melt blended into most polymers (except PET) they are designed to activate at low temperatures. Hence, they cannot remain in the extruder barrel for too long. As soon as the blend is made the MFI increases significantly. Thus if the Phyrolex is injected into the molten polymer, the extrusion end of the barrel can be and must be at a lower temperature than the melt zone.
This means to produce a flame retarded version of the polymer it is necessary to start with the feed stock at a much lower MFI. For example a PP with MFI of 1 will become 12-13 if 30% Phyrolex is blended in.
How much Phyrolex LFR do I need?
- This depends entirely on the target fire test rating being sought. As a rule of thumb to meet the severest conditions like EN 45545 HL3, Euroclass B, an OEL above 34% and an FPA class A(ASTM E84), you need about 30% on resin solids.
Can I use Phyrolex in latex emulsions?
- Yes, but the Phyrolex may disrupt the emulsion. A good starting point is to seek a resin the pH below 6.0 . However, the Phyrolex LFR is a plasticiser and will lower both the MFFT and Tg. Hence, a fully flame retarded film will be soft. An emulsion with a very high MFFT and Tg is needed for hard films, This does not affect gunable sealants. These can easily be made with just two components, the Phyrolex LFR and the Acrylic resin
Can I use Phyrolex LFR in solvent based coatings?
- Yes, while the Phyrolex LFRs are apparently polar they produce considerable shifts in the Hansen solubility parameters. The TEAS diagrams are shown in the Phyrolex LFR brochure. For example Phyrolex LFR 2L00 and 3L95 are insoluble in Styrene but will disperse and cure in unsaturated polyesters. Likewise the Phyrolex LFR’s are insoluble in Xylene and White Spirit but they will disperse in Short Chain Oil Alkyds.
An excellent flame retardant varnish can be made with Phyrolex LFR 2L95 dispersed into CAB in Dowanol PM.
Can I use Phyrolex LFR’s in PU and PIR?
- Phyrolex LFR’s are compatible in all portions with the polyols used in PU and PIR. Excellent flame retardant foams, intumescent elastomers and large vehicle coatings have been formulated with Phyrolex LFR’s.
Can I use Phyrolex LFR in Thin Film Intumescents?
- Yes and No. An excellent two pack product can be made on Phyrolex PCP, but this only suitable for factory application. However, Phyrolex 1H85 can be added to conventional APP water based intumescents to give an uplift in DFT efficiency.
Are there any significant problems?
- In free radical curing systems the Phyrolex LFR’s may complex the accelerator, particularly cobalt oxyacids. Other accelerators appropriate to the system should be evaluated.
The pH of the Phyrolex LFR’s may appear low but this is a function of the zwitter ion used in the synthesis. Phyrolex LFR’s are non corrosive, non flammable, non toxic and free from REACH requirements.