FRPM 2017, 3 – 6 July, Manchester, UK

New developments in FR coatings and textiles

S. Bourbigot*, M. Jimenez and S. Duquesne

R2Fire group/UMET – UMR/CNRS 8207, ENSCL, University of Lille, Avenue Dimitri Mendeleïev – Bât. C7a, CS 90108, 59652 Villeneuve d’Ascq Cedex, France

*serge.bourbigot@ensc-lille.fr

Main Message. How to provide high effective protection against fire using protective coatings on several types of substrates.

Key words. Coating, intumescence, fire protection

Abstract The use of coating, or in a more general way surface treatment, is one of the easiest and one of the most efficient ways to protect materials against fire1. It has several advantages: it does not modify the the mechanical properties of the substrates, it is easily processed and it can be used onto diverse materials such as metallic materials2, polymers3, foams4 and textiles5. Moreover, while inflammation occurs usually on the surface of a material it is important to concentrate the protective action at this location. It is the goal of this paper to review recent approaches based on the literature and on our own research to make fire protective coatings for different types of substrates.

When evaluating the fire behavior of materials, we should distinguish between the reaction to fire (contribution of the material to fire growth) and the resistance to fire (defined as the ability of materials to resist the passage of fire and/or gaseous products of combustion). It means that different scenarios should be considered and hence, different thermal constraints are applied on the protective coatings. According to the fire scenario, the FR coating must be therefore designed with the appropriate chemical composition, thickness, thermophysical and thermooptical properties. It will be discussed in the talk.

A typical example of protective coating is intumescent coating. When heated beyond a critical temperature, the intumescent material begins to swell and then to expand forming an insulative coating limiting heat and mass transfer. Intumescence is a versatile method for providing both reaction and resistance to fire to materials. It can be applied on carbon fiber reinforced polymer (CFRP) used in aircraft structure for fire protection (resistance to fire). The intumescent coating must resist to jet fuel fire involving a high heat flux (about 200 kW/m²) and high velocity gases. Mimicking this scenario at the lab scale, it is shown CFRP is protected by an intumescent layer resisting to the jetfire (FIGURE 1 (a)). Intumescent varnish can also be applied on thermoplastics in a cone calorimeter scenario (reaction to fire). It provides outstanding performance on polypropylene since heat release rate remains lower than 10 kW/m² when undergoing an external heat flux of 50 kW/m² (FIGURE 1 (b)).

Coneresidue

(a) (b)

FRPM 2017, 3 – 6 July, Manchester, UK

FIGURE 1. a) development of an intumescent coating at the jet fire test (propane burner, heat flux of 200 kW/m²) protecting CFRP and b) cone calorimeter residue (experiment done at 50 kW/m²) of polypropylene protected by an intumescent varnish.

Other technologies than intumescence are enable to make FR coatings including laber by layer (LbL), sol-gel, plasma deposit, infrared reflective coating … In particular, LbL seems to be one of the most promising way to provide low flammability on numerous substrates (foam, textile and thin thermoplastic films). All those methods will be considered in the talk.

The aim of the talk will be to review methods and apporaches to protect thermoplastics, thermosets, foam, wood, steel, composite and textiles against fire using coatings. A special emphasis will be given on the mechanism of action and the benefit and drawback of this methodology will be discussed.

References 1. S. Bourbigot and S. Duquesne, J. Mater. Chem., 2007, 17(22), 2283-2300.2. J. Alongi, Z. Han, and S. Bourbigot, Prog. Polym. Sci., 2015, 51, 28-73.3. M. Jimenez, H. Gallou, S. Duquesne, C. Jama, S. Bourbigot, X. Couillens, and F. Speroni, J. Fire Sci.,

2012, 30(6), 535-551.4. S. Bellayer, M. Jimenez, S. Barrau, and S. Bourbigot, RSC Advances, 2016, 6(34), 28543-28554.5. M. Jimenez, T. Guin, S. Bellayer, R. Dupretz, S. Bourbigot, and J. C. Grunlan, J. Appl. Polym. Sci.,

2016, 133(32).