Intumescent systems coatings

Protective Coatings. Some flame retardants function by forming a protective Hquid or char barrier. These minimize transpiration of polymer degradation products to the flame front and/or act as an insulating layer to reduce the heat transfer from the flame to the polymer. Phosphoms compounds that decompose to give phosphoric acid and intumescent systems are examples of this category (see Flame retardants, phosphorus flame retardants). 

The use of synergists (micro- and nanoparticles) was also investigated in intumescent coatings. The most recent work conducted is based on the studies done in intumescent bulk polymer (see reaction to fire part). Li et al.108 suggested combining EG and/or molybdenum disilicide (MoSij) in an intumescent system based on APP/PER-melamine. The results show that incorporating the... 

In a recently published work by Bourbigot et al.,63-65 microencapsulation of ammonium phosphate with PU and polyurea shells has been carried out to make an intrinsic intumescent system compatible in normal PU coating for textiles. Microencapsulation of ammonium phosphate helps in reducing the water solubility of the phosphate and hence, increases the durability of the textile back-coating. 

Uses Flame retardant for polyolefins, polyester, pigmented coatings, intumescents, and textiles catalyst in intumescent systems Features Halogen-free provides water resist. 

Uses Flame retardant for polymers, intumescent paints/coatings, plastics (polyesters, polymethyl methacrylate, polyolefins, PS, PU foams), textiles, paper intumescent paint/mastic ingred. catalyst in intumescent systems... 

Uses Flame retardant for plastics, polyolefins, polyester, rubbers, pigmented coatings, latex intumescent coating formulations, paper, textiles catalyst in intumescent systems intumescent paint/mastic ingred. ManuWistrib. Akzo Nobel DSM Chem. N. Am. Great Lakes Miljac ... 

Dimelamine phosphate CAS 56974-60-8 Empihcal C6H15N12O4P Properties Wh. powd. sol. 2 g/l in water m.w. 350.24 dens. 1.66 kg/l dec. 300 C Uses Flame retardant for polymers, intumescent paints/coatings, plastics (polyesters, polymethyl methacrylate, polyolefins, PS, PU foams), textiles, paper intumescent paint/mastic ingred. catalyst in intumescent systems Manuf/Distrib. DSM Chem. N. Am. http //www. dsmna. com Trade Name Synonyms Amgard ND t[Rhodia/Phosphorus Perf. Derivs. 

Pol5mrethane-phosphate combinations ate known to form flame retardant intumescent systems. However, the intumescent formulation caimot be permanent beeause of the water solubility of the phosphate. This problem could be solved by the teehnique of mieroeneapsulation. Microcapsules of diammoniiun hydrogen phosphate (DAHP) with a PU shell are synthesised. Cotton fabrics can be coated with PU formulations that enclose the microeapsules and show a signifieant FR effect. 

The intumescent approach has been used for about 50 years in coatings for the protection of metal and wood structures [1,2]. The introduction of intumescent systems in the bulk of polymeric materials is relatively recent [3-5]. The early developments in intumescent additives for polymers were based on experience acquired in coating applications. Indeed, the empirical approach had led to a recognition of the need for compounds capable of supplying the charred residue (a carbonific ) and of blowing it to a foamed cellular structure ( spumific ) as components of formulations showing intumescent behaviour in coatings. 

In this section we have demonshated that intumescent systems provide efficient fire retardant properties to polymeric materials, both in bulk and as a coating. The mechanisms of action have been discussed and we have seen that the chemistry of such systems offers some flexibility in the synthesis of the char (e.g., potential reactivity of phosphates and oxidized functions). We can then expect to enhance the performance of the intumescent char by the addition of other reactive compounds in the formulation, which is the purpose of the next section. 

These coatings provide the most effective fire-resistant system available but originally were deficient in paint color properties. Since, historically, the intumescence producing chemicals were quite water-soluble, coatings based thereon did not meet the shipping can stability, ease of application, environmental resistance, or aesthetic appeal required of a good protective coating. 

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