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通过使用TGA的无模型和模拟模型方法对PVA聚合物的动力学研究

Zaid Abdulhamid Alhulaybi¹, Ibrahim Dubdub¹

¹Chemical Engineering Department, King Faisal University, P.O. Box 380, Al-Ahsa 31982, Saudi Arabia.

|March 13, 2024

概括

本研究使用热重力测量分析 (TGA) 和多种动力模型研究了聚乙烯醇 (PVA) 的热降解动力学. 研究确定了一种二阶反应是PVA热解最适合的机制.

科学领域:

聚合物科学聚合物科学
材料科学材料科学材料科学
化学动力学化学动力学

背景情况:

聚乙醇 (PVA) 是一种用于纤维,薄膜和膜的多功能聚合物.
了解PVA的热降解对于优化其加工和应用至关重要.
热重力测量分析 (TGA) 是研究聚合物热行为的一个关键技术.

研究的目的:

为了确定聚乙烯醇 (PVA) 热降解的动力参数.
为了比较六种无模型动力学方法的有效性.
为了确定PVA热解最合适的反应机制.

主要方法:

热重力测量分析 (TGA) 在加热速度为20,30和40K分钟-1时进行.
六种无模型方法 (FR,FWO,KAS,STK,K,VY) 用于计算激活能量 (E).
使用Coats-Redfern (CR) 和Criado的主线图的模型拟合确定了反应机制.

主要成果:

TGA揭示了PVA的两个降解阶段,第一阶段 (550-750 K) 分析了动力学.
激活能量 (E) 值在转换范围 (0.1-0.7) 中从104 kJ mol-1 (VY) 到199 kJ mol-1 (FR) 之间.
科茨-雷德费恩方法的平均激活能量为126kJmol-1,第二阶反应 (F2) 被确定为最好的机制.

结论:

PVA的热降解最好用二次反应机制来描述.
使用多种方法的动力分析提供了对PVA热分解的全面了解.
该研究确定了热力学参数 (ΔH, ΔG, ΔS),表明了内热反应过程.

关键词:

在TGA上,TGA就是TGA.分解,分解,分解.运动学的动力学.模型装配-适合模型的没有模特免费的模型.聚乙醇 (PVA) 是一种聚乙醇.

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