Abstract：The salt solution polycondensation method was the main method for industry production of nylon 66, and its prepolymerization process conditions had a direct impact on the product quality. The kinetic model for prepolymerization of nylon 66 salt in aqueous solution was established based on the difference of intramolecular dehydration and terminal amino/terminal carboxyl polycondensation activity of nylon 66. The apparent activation energies and the pre-exponential factors of the intrinsic ion dehydration and terminal amino/terminal carboxyl reversible polycondensation reaction of nylon 66 salt were determined by literature data. The simulated data were in good agreement with literature data. The error was smaller than that calculated from the equivalent activity model. Based on the content of nylon 66 in the polymer of less than 10-6 mol/g, the prepolymerization time should be more than 1.7 h calculated by the model under the reaction conditions with molar ratio of water to nylon 66 salt of 6.23 and the reaction temperature of 220 °C. Compared with the nylon 66 final polymer under the reactions conditions with prepolymerization time of 0.5 h, the nylon 66 final polymer with the prepolymerization time of 2 h had less oligomer content in polymer, better thermal and mechanical. The established model can be used to guide the optimization of the process conditions for salt solution prepolymerization.
Zhu Jun,Gu Xueping,Feng Lianfang et al. Establishment of Kinetic Model for Prepolymerization of Nylon 66 Salt in Aqueous Solution[J]. 化学反应工程与工艺, 2018, 34(2): 145-150.
