Foam, advantages Phenolic

Of recent works we would like to mention first of all the preparation of multi-component phenolic-based methane foams These materials combine the advantages of the initial components (fire resistance of phenolic and high strength of polyurethane foams), whereas their shortcomings (friability and high water-absorption of phenolic and flammability of polyurethane foams) are suppressed to a considerable extent. 

The Naval Ammunition Depot (NAD) at Crane, Indiana has developed improved fire-retardant phenolic foams containing blends of boric/oxalic acids as catalysts, as described above. The resultant foams were found to be extremely efficient fire barriers due to their high heat absorptivity, the amount of carbon and/or coke produced during pyrolysis, and the adhesion of the char to the burned materials. Other advantages of the foam during flaming and nonflaming pyrolysis are its low smoke emissions and lack of toxic fumes other than carbon monoxide. It takes one hour to reach 230°F (110°C) when a 13 Ib/tf (208 kg/m ) phenolic foam specimen 2.9 inches (7.4 cm) is exposed to a fully developed fire (41). 

Foamed phenolic polymer appears to be an excellent insulator, stable and cheap. There is much competition for similar outlets between thermosets and thermoplastics—urea and melamine, ABS, acetal, PP and Nylon. The phenolics have the advantage of low price, and a good combination of general performance when appropriately composed. On the other hand, use of thermoplastics is frequently preferable due to improved processing in mass production, in addition to the recyclability of wastes. 

Phenolic Microballoons applications in plastics take advantage of low density, porosity, and surface-to-volume ratio to produce lightweight parts. Probably the most notable example is the syntactic foam. 

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