基于二苯基甲烷二异氰酸酯的聚氨酯弹性体的固化动力学

Curing Kinetics of Methylene Diphenyl Diisocyanate-Based Polyurethane Elastomers.

作者信息

Liu Shuang, Li Xiaodong, Ge Mengchen, Du Xujie, Zou Meishuai

机构信息

School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.

System Design Institute of Hubei Aerospace Technology Academy, Wuhan 432000, China.

出版信息

Polymers (Basel). 2022 Aug 27;14(17):3525. doi: 10.3390/polym14173525.

DOI:10.3390/polym14173525

PMID:36080600

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9459966/

Abstract

The curing kinetics of MDI-based polyurethane elastomers were studied by non-isothermal differential scanning calorimetry (DSC). The kinetic parameters of the reaction system were calculated by the Kissinger method. The changing activation energy was observed by the Flynn−Wall−Ozawa method and the Friedman method. The results of model free fitting showed that the curing reaction could be divided into two stages, showing a change in reaction order when α > 0.45 and a piecewise curing mechanism function of the MDI-based polyurethane elastomers reaction system was deduced by autocatalytic model. The extrapolation method was used to determine the optimum curing conditions for the system, which can accurately describe the curing process. In addition, the optimal curing conditions are when: the constant temperature curing temperature of the system is 81 °C, the curing time is 29 min, and the post-curing temperature is 203 °C.

摘要

采用非等温差示扫描量热法（DSC）研究了基于MDI的聚氨酯弹性体的固化动力学。通过基辛格方法计算了反应体系的动力学参数。采用弗林-沃尔-小泽方法和弗里德曼方法观察了变化的活化能。无模型拟合结果表明，固化反应可分为两个阶段，当α>0.45时反应级数发生变化，并通过自催化模型推导了基于MDI的聚氨酯弹性体反应体系的分段固化机理函数。采用外推法确定了体系的最佳固化条件，该条件能准确描述固化过程。此外，最佳固化条件为：体系恒温固化温度为81℃，固化时间为29min，后固化温度为203℃。