Phase relations and decomposition for systems of diethylamine hydrochloride-adipic acid and diethylamine hydrochloride-sebacic acid

Phase diagrams and decomposition for systems of (C2H5)(2)NH . HCl-C6H10O4 ( adipic acid) and (C2H5)(2)NH . HCl-C10H18O4 (sebacic acid) have been invest igated by DTA, DSC and visual polythermal methods. Both two systems are of the simple eutectic type. Eutectics are located in 50% of C6H10O4 at 94 deg rees C and 55% of C10H18O4 at 106 degrees C respectively. (C2H5)(2)NH . HCl melts at 217 degrees C and decomposes as soon as it just melted. A polymor phic reaction of (C2H5)(2)NH . HCl occurs at 98 degrees C, the transition h eat is 29.7 J/g. Experiments also revealed that adipic acid melts at 152.8- 155.7 degrees C with melting heat 199.1 J/g, decomposes at 250.8-263.0 degr ees C with decomposition heat 174.2 J/g; sebacic acid melts at 133.1-135.9 degrees C with melting heat 1.99.8 J/g and decomposes at 233.2-269.2 degree s C, but no exact value of decomposition heat has been determined.