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The effects of salt, molecular weightand viscosity, and mass ratioon the apparent activation energy of the cross-linking reaction ofepoxy resins and protein hydrolysate were studied by nonisothermaldifferential scanning calorimetry. The Kissinger equation, the model-freeisoconversional method, and the autocatalytic model were used to analyzethe kinetic data. The presence of salts contributed to an increasein the apparent activation energy. The curing of epoxy resins withlower molecular weight protein hydrolysates was found to have loweractivation energy and order of reaction. An increase in the concentrationof curing groups resulted in a small increase in the order of reaction.The activation energy of curing bisphenol A diglycidyl ether (DGEBA),with viscosity 500–700 cP, was found to be significantly higherthan the curing activation energy of polypropylene glycol diglycidylether (PPGDE), which has a viscosity of 50 cP. [ABSTRACT FROM AUTHOR]

Theeffects of salt, water, and temperature on the cross-linking of peptoneswith glutaraldehyde were studied. At low reaction temperatures, aminegroups from peptones form Schiff bases with carbonyl groups of glutaraldehyde.The resulting CN bond is weak and can be easily broken byheat or dissolution in water. As the reaction temperature is increased,the more stable CN bond is formed. A network with low watersolubility and significantly improved thermal stability is produced.The presence of salt (sodium chloride) increases the miscibility ofpeptones and glutaraldehyde solution but also increases the watersolubility of the final product. The presence of water also has adual effect. Water acts as a medium to disperse peptones into glutaraldehydeand is also a hydrogen source to drive the reaction forward. However,water is a byproduct of the reaction. Its presence suppresses thereaction from the standpoint of thermodynamic equilibrium, and itmust therefore be driven off (by heat). [ABSTRACT FROM AUTHOR]