Journal of Applied Polymer Science, Vol.88, No.5, 1252-1257, 2003
New process for the production of dry hexamethylenediammonium adipate
A simple and easy technique is proposed for the preparation of dry hexamethylenediammonium adipate (HMA salt), using conventional dry-blending equipment. The process includes contacting adipic acid and hexamethylenediamine, in the presence of a cryogenic medium, which is used to depress the exothermic of the salt formation. The purpose is the formation of free-flowing HMA salt with good homogeneity and balanced end groups, which can be used as a starting intermediate in the polyamide industry. Critical parameters were studied, such as the nature and amount of cryogenic agent and the presence of water traces in the reacting mixture. Application in an industrial scale seems feasible so that all advantages of handling dry HMA salt instead of its components (adipic acid powder and hexamethylenediamine liquid) can be utilized. (C) 2003 Wiley Periodicals, Inc.