Kinetic Study of the Urethane and Urea Reactions of Isophorone Diisocyanate
Kinetic Study of the Urethane and Urea Reactions of Isophorone Diisocyanate
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DOI：
10.1002/app.27421
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发表时间：
2008-03
影响因子：
3
通讯作者：
Jin‐Lin Han;C. H. Yu;Yan‐Cheng Lin;K. Hsieh
中科院分区：
文献类型：
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作者：
Jin‐Lin Han;C. H. Yu;Yan‐Cheng Lin;K. Hsieh
用傅里叶变换红外光谱研究了异佛尔酮二异氰酸酯(IPDI)与醇的催化氨基甲酸酯反应动力学和端异氰酸酯端基预聚体[IPDI-PPG2000-IPDI]与水的尿素反应动力学。以月桂酸二丁基锡为氨基甲酸酯反应催化剂，以不同叔胺为催化剂进行尿素反应。通过监测红外光谱中NCO在2270 cm−1处伸缩吸收带强度的变化来跟踪反应，通过对不同温度(30-60°C)下的动力学数据的评估来确定活化参数。动力学数据表明，异氰酸酯/醇和异氰酸酯/水的反应在初始阶段都遵循二级动力学，但后来由于羟基与新生成的氨酯和尿素基团之间氢键的自催化作用而遵循三级动力学。此外，异氰酸酯/醇和异氰酸酯/水反应的活化能分别为64.88和约80kJ/mol，表明尿素生成反应对反应温度比氨酯生成反应更敏感。©2007 Wiley期刊，Inc.J Appl Polym Sci 2008
Kinetic studies of the catalyzed urethane reactions between isophorone diisocyanate (IPDI) and alcohols and of the urea reactions between an isocyanate-terminated prepolymer [IPDI–PPG2000–IPDI, where PPG2000 is poly(propylene glycol) with a number-average molecular weight of 2000 g/mol] and water in the bulk state were performed with Fourier transform infrared (FTIR) spectroscopy. Dibutyltin dilaurate was used as the catalyst for the urethane reaction, and various tertiary amines were used as catalysts for the urea reactions. The reactions were followed through the monitoring of the change in the intensity of the absorbance band for NCO stretching at 2270 cm−1 in the FTIR spectra; the activation parameters were determined through the evaluation of the kinetic data obtained at various temperatures (within the range of 30–60°C). The kinetic data indicated that the catalyzed isocyanate/alcohol and isocyanate/water reactions both followed second-order kinetics during their initial stages but later followed third-order kinetics resulting from the autocatalytic effects of hydrogen bonding between the hydroxyl groups and the newly formed urethane and urea groups. Furthermore, activation energies of 64.88 and about 80 kJ/mol for the isocyanate/alcohol and isocyanate/water reactions, respectively, indicated that the urea-forming reactions were more sensitive to the reaction temperature than the urethane-forming reactions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008