Epoxy reaction mechanism anhydride cured, catalysts

Anhydride Cured Epoxy Reaction Mechanism. In the case of anhydride cured epoxy reaction, catalysts will promote ring opening of the anhydride to provide carboxylic group for reaction with epoxide. Without catalysts, the reactions are slow and accompanied by extensive epoxide homopolymerization at elevated temperatures. 

Tanaka and Kakiuchi (6) proposed catalyst activation via a hydrogen donor such as an alcohol as a refinement to the mechanism discussed by Fischer (7) for anhydride cured epoxies in the presence of a tertiary amine. The basic catalyst eliminates esterification reactions (8). Shechter and Wynstra ( ) further observed that at reaction conditions BDMA does not produce a homopolymerization of oxiranes. 

As thermosetting materials, epoxy resins can be cured either by anhydride through the condensation reaction mechanism using amine as the catalyst or by cationic... 

A study has been undertaken to attempt to determine a possible mechanism for the crosslinking of an epoxy resin with phthalic anhydride using an imidazole derivative as the catalyst. In this study we have used differential scanning calorimetry (DSC) to measure the heat of reaction and time of curing process. 

L6WiS BaS6S. Lewis bases contain an unshared pair of electrons in an outer orbital and seek reaction with areas of low electron density. They can function as nucleophilic catalytic curing agents for epoxy homopolymerization as cocuring agents for primary amines, polyamides, and amidoamines and as catalysts for anhydrides. Tertiary amines and imidazoles are the most commonly used nucleophilic catalysts. Several different mechanisms are possible ... 

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