Studies on polycondensation reactions of nylon salt. II.. The rate of polycondensation reaction of nylon 66 salt in the presence of water

The polycondensation reaction of hexamethylenediammonium adipate (nylon 66 salt) has been studied in the presence of water in 0.5–10.0 molar ratio. The reaction proceeds extremely fast and reaches equilibrium after about 5 hours at 200‐220°C. The apparent equilibrium constant between chain molecules increases with the decrease of water content or with the rise of temperature. The apparent heat of the reaction is –2 to 6 kcal./mole and the polycondensation reaction in the presence of large quantity of water is an endothermic reaction. The polycondensation of nylon 66 salt is proved to be a second order reaction with the activation energy of 22 kcal./mole.