The molecular weight distribution (MWD) of polymers is a target of the optimization and control of industrial polymerization processes, as it dictates the processability and properties of polymers. A method, named as segment probability method, is developed to calculate the MWD of polycondensates produced by monomers of types A₂ and B₂ in a continuous reactor. It considers a growing chain as being composed of A and B segments in the middle of the chain and two terminal segments at the chain ends. It calculates the propagation probabilities of these different types of segments upon taking into account both the polycondensation and side reaction kinetics as well as the residence time distribution of the continuous reactor. The method is validated by poly(butylene terephthalate) (PBT) obtained from an industrial polymerization process composed of a continuous esterification reactor. The MWDs of the PBT calculated by this method are in agreement with those measured by size exclusion chromatography with mean square errors less than 10%.

中文翻译：

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一种计算连续反应器中线性缩聚物分子量分布的分段概率法

聚合物的分子量分布 (MWD) 是工业聚合过程优化和控制的目标，因为它决定了聚合物的可加工性和性能。开发了一种称为链段概率法的方法来计算由A ₂和B _{2型单体生产的缩聚物的MWD}在连续反应器中。它认为一条生长链由链中间的 A 和 B 段以及链末端的两个末端段组成。它在考虑缩聚和副反应动力学以及连续反应器的停留时间分布的情况下计算这些不同类型片段的传播概率。该方法通过由连续酯化反应器组成的工业聚合过程中获得的聚对苯二甲酸丁二醇酯 (PBT) 进行验证。通过该方法计算得到的 PBT 的 MWD 与通过尺寸排阻色谱法测量的结果一致，均方误差小于 10%。