Simulation of irreversible and reversible degradation kinetics of linear polymers using sectional moment method
Simulation of irreversible and reversible degradation kinetics of linear polymers using sectional moment method
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DOI：
10.1016/j.ces.2023.118711
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发表时间：
2023-04-08
影响因子：
4.7
通讯作者：
Zhou，Yin-Ning
中科院分区：
文献类型：
--
作者：
Wang，Jiang;Wang，Tian -Tian;Zhou，Yin-Ning
在聚合物反应工程领域，准确模拟聚合物降解过程有助于了解反应动力学，指导降解反应器的设计、运行和控制。在此基础上，提出了一种基于矩量法的分段策略，该策略具有新定义的临界链长，可以较低的计算成本模拟线性聚合物的降解过程。通过计算低摩尔质量物质（如二聚体）的浓度，该模型可以高精度地模拟聚合物线性降解过程中平均性质和浓度物质的演变。此外，还利用已建立的模型对摩尔质量分布的演变进行了近似。同时进行随机断裂和不可逆/可逆链端断裂过程的敏感性分析。结果表明，随机断裂（kr）、链端断裂（ke）及其逆反应（k-e）的速率系数可调节单体产率、平均和分布分子性质。最后，通过开发的基于mom的模型对聚乳酸醇解体系进行了动力学分析，验证了模型的准确性和适用性。本工作为模拟聚合物线性降解提供了一种新的方法，从而揭示了降解过程中的动力学演变。
In the field of polymer reaction engineering, accurately simulating polymer degradation process is beneficial to understand the reaction kinetics, which guides the design, operation, and control of the degradation reactor. Herein, a sectional strategy based on the method of moments with a newly defined critical chain length was proposed to simulate the degradation process of linear polymers with low computational cost. By accounting for the concentration of species with low molar mass (e.g., dimer), the evolution of average properties and concentration polymer species during linear polymer degradation were simulated with high accuracy through this model. In addition, the evolution of molar mass distribution was approximated by using the as-developed model. Sensitivity analysis was performed for simultaneous random scission and irreversible/reversible chain-end scission processes. Results show that monomer yields, average and distributed molecular properties can be tuned by the rate coefficients of random scission (kr), chain-end scission (ke), and its reverse reaction (k-e). Finally, kinetic insights into the polylactic acid alcoholysis system were gained by the as-developed MoM-based model, which demonstrates the accuracy and applicability of the model. This work provides a new method for simulating linear polymer degradation, and thus revealing the kinetic evolution during degradation.