Preparation of propylene/1-butene polymer alloys by monomer composition switching polymerization: kinetic and reactor models

doi:10.11949/j.issn.0438-1157.20180984

Abstract

Abstract:

Propylene/1-butene polymer alloys were prepared by in-situ slurry polymerization with spherical supported Ziegler-Natta catalyst and the technology of monomer composition switching method. Combining the kinetic model of propylene/1-butene copolymerization and the material balance, a reactor model with the monomer composition switching was developed by the moment method. The model parameters were fitted according to the real-time consumption rate of propylene obtained from experiments. The polymerization reactivity, the product's composition and their changes with switching frequency of monomer composition were simulated. The results show that the model can well describe the polymerization rate at different stages, the catalyst activity, the total content of 1-butene in the alloy, and the contents of random copolymer and “block” copolymer at various switching frequencies. It has been revealed also that the pulse feed of propylene in the copolymerization process is conducive to increasing the monomer diffusion to the active center, thereby increasing the polymerization rate and polymerization activity.

Key words: polymers, synthesis, reaction kinetics, reactors, mathematical modeling

摘要：

采用球形负载型Ziegler-Natta催化剂和单体组成周期性切换的丙丁淤浆共聚合技术，原位制备了聚丙烯/丙丁共聚物合金。将共聚动力学的矩模型与物料衡算相结合，首次建立了单体组成切换的共聚反应器模型。依据实验所得的丙烯实时消耗速率拟合得到模型参数，并模拟计算了不同单体组成切换频率下的聚合反应活性和聚合产物的组成。结果表明，模型能很好地描述各切换频率下丙烯的聚合速率曲线、催化聚合活性，以及合金中1-丁烯的总含量、丙丁无规共聚物的含量和“嵌段”共聚物的含量等。结果还显示，共聚过程中丙烯的脉冲进料有利于提高单体向活性中心的扩散，进而提高聚合速率和聚合活性。

关键词: 聚合物, 合成, 反应动力学, 反应器, 数学模拟

CLC Number:

TQ325.1

HUANG Kai, ZHENG Zheng, HU Jijiang, FENG Lianfang, LI Bogeng. Preparation of propylene/1-butene polymer alloys by monomer composition switching polymerization: kinetic and reactor models[J]. CIESC Journal, 2018, 69(11): 4693-4701.

黄凯, 郑征, 胡激江, 冯连芳, 李伯耿. 丙烯/1-丁烯聚合物合金的单体组成切换法制备：动力学及聚合器模型[J]. 化工学报, 2018, 69(11): 4693-4701.

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