The research of polymerization kinetics and reaction mechanism on flame-retardant polyamide 66 (FRPA66) is of great significance for its industrial production. Here, FRPA66 is prepared by one-step melt polycondensation of nylon 66 salt and a reactive flame retardant DPDA. By exploring the relationship of viscosity-average molecular weight versus reaction time at different polymerization stages, the apparent rate constant of FRPA66 is calculated to be 41.8 dL gs. Besides, molecular simulation analysis demonstrates that the reaction activation energy of DPDA and nylon 66 salt in pre-polymerization stage is 312.04 kcal/mol, indicating that the pre-polymerization time can be extended to make up for the lack of pre-polymerization power of FRPA66. In the final polymerization stage, reasonable control of releasing pressure and polymerization time can promote the self-condensation of a small part of DPDA, thus improving the molecular weight of FRPA66. Finally, based on the polymerization kinetic and reaction mechanism, FRPA66 containing 5% DPDA can reach V-0 level.

中文翻译：

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共聚阻燃聚酰胺66聚合动力学研究：表观速率常数和反应活化能

阻燃聚酰胺66（FRPA66）的聚合动力学和反应机理研究对其工业化生产具有重要意义。在此，FRPA66是通过尼龙66盐和反应型阻燃剂DPDA的一步熔融缩聚制备的。通过探索不同聚合阶段粘均分子量与反应时间的关系，计算出FRPA66的表观速率常数为41.8 dL gs。此外，分子模拟分析表明，预聚阶段DPDA与尼龙66盐的反应活化能为312.04 kcal/mol，表明可以延长预聚时间来弥补预聚力的不足。 FRPA66。在聚合末期，合理控制释放压力和聚合时间，可以促进少部分DPDA自缩合，从而提高FRPA66的分子量。最后，根据聚合动力学和反应机理，含有5%DPDA的FRPA66可以达到V-0级别。