Abstract:

In order to solve the problems of high energy consumption, low production efficiency and poor product quality caused by high reaction temperature and long reaction time in the process of semi-aromatic polyamide polymerization, powder semi-aromatic polyamide PA12T was prepared by direct solid state polymerization (DSSP) with PA12T salt as raw material. The influence of polymerization process on the intrinsic viscosity and nascent state of the product was systematically studied, and the optimized process conditions were obtained. Different heating rates were also used to ensure the material being always in a solid state during the polymerization process, the room temperature rose to 180℃ at the rate of 3℃/min (180℃ was the first predetermined temperature), and then rose from 180℃ to 210℃ (210℃ was the second predetermined temperature) in the way of step heating with heating rate of 5℃ within 30 minutes. The volume ratio of water consumption and equipment was 25g/L and holding time in the negative pressure stage was 1—6h. The maximum reaction temperature was 210℃ and the time was 7—12h in the whole polymerization process. The intrinsic viscosity of the product was 0.80—1.73dL/g, the melting point was 317℃, the initial thermal decomposition temperature was 392℃, the tensile strength was 76.1MPa, the elongation at break was 39.4%, the bending strength was 42.6MPa and the notch impact strength was 9.47kJ/m².

Key words: direct solid state polymerization, polymers, polyamide PA12T, thermal properties, mechanical properties

摘要：

为了解决半芳香聚酰胺聚合过程中存在的反应温度高、反应时间长所带来的能耗高、生产效率低、产品质量欠佳的问题，本文以PA12T盐为原料，通过直接固相聚合（DSSP）的方法制备粉末状半芳香聚酰胺PA12T。系统研究聚合工艺对产物特性黏数和初生态的影响，得到优化的工艺条件。为实现反应物料在聚合过程中始终处于固体状态，采用了不同升温速率的方法：先以3℃/min的速率从室温升至180℃（180℃为第一预定温度），再以阶梯升温的方式从180℃逐步升至210℃（210℃为第二预定温度），升温速率为每30min 5℃，水用量与设备的体积比为25g/L，负压保温时间为1~6h。整个聚合过程的最高反应温度为210℃，时间为7~12h。得到产物的特性黏数为0.80~1.73dL/g，熔点为317℃，初始热分解温度为392℃，拉伸强度为76.1MPa，断裂伸长率为39.4%，弯曲强度为42.6MPa，缺口冲击强度为9.47kJ/m²。

关键词: 直接固相聚合, 聚合物, 聚酰胺PA12T, 热性能, 力学性能