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首页> 外文期刊>Journal of Applied Polymer Science >Reaction Kinetics for Solid-State Polymerization of Poly(ethylene terephthalate)
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Reaction Kinetics for Solid-State Polymerization of Poly(ethylene terephthalate)

机译：聚对苯二甲酸乙二醇酯固相聚合的反应动力学

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摘要

A simple kinetic model capable of describing the behaviors of solid-state polymerization (SSP) of poly(ethylene terephthalate) (PET) has been developed. Ac- cording to this model, there are two types of end groups, namely active end groups and inactive end groups, and the solid-state polycondensation reaction is a second-order reaction with respect to the active end group concentration. The inactive end groups include chemically dead end groups and functional end groups that are immobilized by the crystalline structure. The inactive end group concentration determines the ultimate -intrinsic viscosity (IV) or molecular weight achievable in the SSP-the lower the inactive end group concentration, the higher the ultimate IV. Four pulverized PET prepolymers with IV values ranging from 0.20 to 0.35 dUg were solid-state polymerized in a fluid-bed reactor at temperatures between 200 and 230degC to generate data to test the model. The experimental results fit the proposed rate equations very well, confirm- ing the adequacy of the proposed kinetic model. Under these SSP conditions, the activation energy is about 23.6 kca1/mol and the average SSP rate about doubles with each l0degC increase in temperature. The rate constant increases, while the inactive end group concentration decreases, with increasing temperature and prepolymer IV. This explains why the reaction rate and the ultimate IV increase with increasing prepolymer IV as well as temperature in the SSP of PET.
机译：已经开发出一种简单的动力学模型，该模型能够描述聚对苯二甲酸乙二酯（PET）的固态聚合（SSP）行为。根据该模型，有两种类型的端基，即活性端基和非活性端基，固态缩聚反应是相对于活性端基浓度的二级反应。非活性端基包括通过晶体结构固定的化学上的死端基和功能性端基。非活性端基浓度决定了在SSP中可达到的极限-固有粘度（IV）或分子量-非活性端基浓度越低，极限IV越高。 IV值在0.20至0.35 dUg范围内的四种粉碎的PET预聚物在流化床反应器中于200至230摄氏度之间进行固态聚合，以生成数据以测试模型。实验结果很好地拟合了所提出的速率方程，证实了所提出动力学模型的充分性。在这些SSP条件下，活化能约为23.6 kca1 / mol，随着温度每升高10℃，SSP的平均速率大约增加一倍。随着温度和预聚物IV的增加，速率常数增加，而非活性端基浓度降低。这解释了为什么反应速率和最终IV随着预聚物IV的增加以及PET SSP中温度的增加而增加。

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