Abstract
Thermoset resin systems comprising phenols, epoxies and polyfurfuryl alcohol have been used for more than 20 years in the aerospace, automotive, marine and construction sectors where fire and high temperature resistant components are required. The resins, mentioned above, are cured by acid, neutral or alkaline catalysts. Since the reactions are exothermic in nature, the curing process sometimes leads to explosions. It is important, therefore, to review the patents related to the catalysts used in the curing of these resins. Recently, a US patent was filed by the author where it has shown the ways to reduce the chances of explosions frequently observed during the acid catalyzed condensation reactions of polyfurfuryl alcohol. Other patents granted in 2011, show the use of latent curing agents (US8039522 and US7906213) and phenol as a curing agent for epoxy resins (US8008410). A method for producing a thermosetting epoxy resin having a benzoxazine ring is mentioned in US7994270. Carboxylic acids, sulfonic acids and phosphonic acids having at least two acid groups as an acid curing agent for thermoset resins are discussed in US8003750.
Keywords: Acid catalysts, alkaline catalysts, epoxy resins, phenolic resins, polyfurfuryl alcohol resins.
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