用在线红外光谱跟踪1,3-双（3-氨基甲酸甲酯基-4-甲基苯基）脲二酮的开环反应,研究了温度、催化剂等对脲二酮开环反应的影响;同时,进行了脲二酮开环-氨酯化反应,用核磁共振（NMR）表征了产物甲苯-二（2-甲基-4-乙基）氨基甲酸酯的结构。结果表明,温度为80℃、催化剂三正丁基膦用量为m（cat）/m（uretedione）=4/100时,脲二酮开环反应比较完全;在三正丁基膦的催化下,可能会发生异氰酸酯三聚反应,导致异氰酸酯基浓度呈现先增大后减小的变化规律。此外,与乙醇反应时,脲二酮的开环、氨酯化同时进行,氨酯化速率大于开环速率,使产物具有规整的结构。
Ring-opening reaction of 1,3-bis（3-methyl carbamyl-4-methyl phenyl）uretedione was investigated with in-situ Fourier transform infrared spectrum（FT-IR）,and the effects of temperature and catalyst on the reaction was discussed.Carbamate reaction of ring-opened uretedione was also studied,and the product of tolylene-bis-（2-methyl-4-ethyl）carbamate was characterized with IR and nuclear magnetic resonance spectrum（NMR）.It shows that ring-opening reaction carries on completely when the reaction temperature is 80 ℃ and the mass percent of tri-n-butyl phosphine is m（cat）/m（uretedione）=4/100.Trimerization of isocyanate may be also happened in the presence of tri-n-butyl phosphine,which leads to the-NCO concentration first larger and then smaller.Furthermore,the ring-opening reaction and carbamate reaction happens together when reacting with alcohol.The rate of carbamate reaction is faster than that of ring-opening reaction,which enables good structure regularity of the product.
参考文献
| [1] | Wicks Douglas A.;Wicks Zeno W. Jr. .Blocked isocyanates III: Part A. Mechanisms and chemistry[J].Progress in Organic Coatings: An International Review Journal,1999(3):148-172. |
| [2] | 阎宏永,刘翠云,付青存,宋文生,李国芝,张玉清.异氰酸酯改性与应用[J].涂料工业,2007(08):63-66. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%