Melt Polycondensation In A Rotating Disc Reactor

熔融缩聚技术被用于聚合物中。 用于合成热塑性塑料的聚合物工业， 特种聚合物。 例如，饱和聚酯（如 作为聚（对苯二甲酸乙二醇酯）-PET和聚（丁烯 对苯二甲酸酯）-PBT），聚酰胺，聚芳酯，和 聚碳酸酯以半间歇或间歇方式制造， 连续缩聚反应器。 许多这些过程 具有多个反应阶段和复杂 反应网络会产生各种不需要的边 产品. 纯熔融单体在聚合反应器中聚合。 无添加溶剂-更环保 这是一种比其他工业聚合方法更好的方法。 的 该方法也是有利的，因为聚合物可以 直接造粒或纺成纤维。 工业熔融缩聚工艺的一个共同特点 采用多个反应阶段， 反应堆串联。 对于PET生产， 反应过程包括：（a）单体，低分子量 重量低聚物和低分子量预聚物， 在连续搅拌釜式反应器中合成，和（B） 然后将预聚物聚合到更高的分子量 聚合物在完成聚合反应器（通常是旋转的 圆盘反应器），其中大的气-液表面积 提供了 最终的聚合物产品性能主要是 在该最终聚合阶段中进行调节，因此 该反应器优化设计和操作是重要的 也是本研究的目的。 具体而言，PI将解决以下问题： (1)什么是影响形成的主要因素 在旋转圆盘上的聚合物薄膜 有哪些 圆盘设计/操作之间的定量关系 变量和薄膜厚度？ (2)凝结气泡的作用是什么 传质过程中的副产物？ 一个人怎么能 量化气泡对总蒸汽的影响- 液相传质速率 (3)相邻的圆盘之间发生了什么相互作用， 什么将是多个光盘的最佳布局， 搅拌器轴？ 圆盘的最佳角度是多少 浸在液体池里 (4)什么是整体液体（聚合物熔体）流动模式， 反应堆？ (5)连续精整反应器在以下条件下的性能如何 各种反应器操作条件和进料条件 在稳态和瞬态时，？ 什么聚合物 什么反应堆对性能影响最大 变量？应该如何配对聚合物属性 反应器操作条件的参数， 产品质量控制体系的设计？ 实验工作和反应堆建模都将完成。*//

Melt condensation polymerization techniques are used in the polymer industry for the synthesis of thermoplastics and specialty polymers. For example, saturated polyesters (such as poly(ethylene terephthalate) - PET and poly(butylene terephthalate) - PBT), polyamides, polyarylates, and polycarbonates are manufactured in either semi-batch or continuous polycondensation reactors. Many of these processes are characterized by multiple reaction stages and complex reaction networks that give rise to various unwanted side products. The pure molten monomers are polymerized in the absence of added solvents - a more environmentally friendly process than other industrial polymerization processes. The process is also advantageous because the polymers can be directly pelletized or spun into fibers. A common feature of industrial melt polycondensation processes is that multiple reaction stages are employed using several reactors in series. For PET production, the sequential reaction procedure includes: (a) monomers, low molecular weight oligomers, and low molecular weight prepolymers are synthesized in continuous stirred tank reactors, and (b) the prepolymers are then polymerized to higher molecular weight polymers in finishing polymerization reactors (often rotating disc reactors) where large vapor-liquid surface areas are provided. The final polymer product properties are mostly regulated in this finishing polymerization stage, therefore the optimal design and operation of this reactor is important and is the objective this research. Specifically, the PI will address the following questions: (1) What are the major factors that affect the formation of polymer films on a rotating disc? What are the quantitative relations between the disc design/operating variables and film thickness? (2) What is the role of gas bubbles of condensation byproducts in the mass transfer process? How can one quantify the effect of gas bubbles on the total vapor- liquid mass transfer rate? (3) What interactions occur between the neighboring discs and what will be the optimal layout of multiple discs on the agitator shaft? What will be the optimal angle of disc immersion in the liquid pool? (4) What is the overall liquid (polymer melt) flow pattern in the reactor? (5) How does the continuous finishing reactor behave under various reactor operating conditions and feed conditions at steady state and transient state? What polymer properties are most strongly influenced by what reactor variables? How should one pair the polymer property parameters with reactor operating conditions for the design of product quality control systems? Both experimental work and reactor modeling will be done.***//