The amount effect of catalyst on the urethane reaction of o-hydroxybenzyl alcohol
The amount effect of catalyst on the urethane reaction of o-hydroxybenzyl alcohol
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DOI：
10.1016/j.cclet.2011.10.013
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发表时间：
2012-02
影响因子：
9.1
通讯作者：
Peng Yang;Y. Yu;S. Wang;Tianduo Li
中科院分区：
文献类型：
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作者：
Peng Yang;Y. Yu;S. Wang;Tianduo Li
用原位红外光谱（FT-IR）对邻羟基苯甲醇与异氰酸苯酯的氨基甲酸乙酯反应进行了监测。以二月桂酸二丁基锡为催化剂，考察了其用量对反应的影响。发现反应开始前有明显的诱导期。有趣的是，诱导时间随二酸二丁基锡浓度的增加先上升后下降。当二月桂酸二丁基锡浓度达到9.58×10−5mol/L时，诱导期完全消失，此后不再出现。并对反应动力学进行了研究。随着二月桂酸二丁基锡浓度的增加，酚基反应速率（k1）急剧增加，而醇基反应速率（k2）总体上变化不大。当二酸二丁基锡浓度在9.58×10−6mol/L到1.92×10−4mol/L范围内变化时，k1增加了约20倍，k2增加了约2倍，使得k1/k2值增大。
The urethane reaction of o-hydroxybenzyl alcohol with phenyl isocyanate was monitored with in situ FT-IR. Dibutyltin dilaurate was used as catalyst and its amount effect was investigated. It was found that there was an obvious induction period before reaction began. It was interesting that the time of induction period climbed up and then declined with the increase of dibutyltin dilaurate. When the concentration of dibutyltin dilaurate reached 9.58×10−5mol/L, the induction period disappeared completely and hereafter did not appear any more. Furthermore, the urethane reaction kinetics was studied. When the concentration of dibutyltin dilaurate increased, the reaction rate of phenolic group (k1) increased sharply, but the reaction rate of alcoholic group (k2) appeared of little change on the whole. k1increased about 20-fold, yet k2increased about 2-fold when the concentration of dibutyltin dilaurate varied from 9.58×10−6mol/L to 1.92×10−4mol/L, which made the value of k1/k2enlarge.