Reaction Mechanism,Synthesis and Characterization of Urea-glyoxal(UG) Resin  

作　　者：DENG Shu-Duan LI Xiang-Hong XIE Xiao-Guang DU Guan-Ben 

机构地区：[1]College of Materials Science and Technology,Beijing Forestry University [2]Yunnan Key Laboratory of Wood Adhesives and Glue Products,Southwest Forestry University [3]School of Chemical Science and Technology,Yunnan University

出　　处：《Chinese Journal of Structural Chemistry》2013年第12期1773-1786,共14页结构化学（英文）

基　　金：Supported by the Key Program of the National Natural Science Foundation of China(No.30930074);National Natural Science Foundation of China(No.31260160)

摘　　要：The reaction mechanism of glyoxal （G） with urea （U） under weak acid condition was theoretically investigated at PW91/DNP/COSMO of quantum chemistry using density functional theory （DFT） method. The results show that the addition reaction of G with U under the conditions mainly involves the reactions of U with protonated glyoxal （p-G）, protonated 2,2-dihy- droxyacetaldehyde （p-G 1） and protonated bis-hemdiol （p-G2） to form two important carbocation reactive intermediates of C-p-UG and C-p-UG1, and two important hydroxyl compounds of UG and UG1. These compounds play important roles in the formation of UG resin. According to the result of quantum chemical calculation, UG resin was synthesized successfully under weak acid conditions. The UG resin was characterized by matrix assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）, ultraviolet and visible spectroscopy （UV-vis）, Fourier transform infrared spectroscopy （FT1R） and nuclear magnetic resonance spectroscopy （13CNMR and 1HNMR）. These instrumental analytical results agree with each other and further confirm the addition reaction pathway of glyoxal with urea proposed by quantum chemical calculation.The reaction mechanism of glyoxal （G） with urea （U） under weak acid condition was theoretically investigated at PW91/DNP/COSMO of quantum chemistry using density functional theory （DFT） method. The results show that the addition reaction of G with U under the conditions mainly involves the reactions of U with protonated glyoxal （p-G）, protonated 2,2-dihy- droxyacetaldehyde （p-G 1） and protonated bis-hemdiol （p-G2） to form two important carbocation reactive intermediates of C-p-UG and C-p-UG1, and two important hydroxyl compounds of UG and UG1. These compounds play important roles in the formation of UG resin. According to the result of quantum chemical calculation, UG resin was synthesized successfully under weak acid conditions. The UG resin was characterized by matrix assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）, ultraviolet and visible spectroscopy （UV-vis）, Fourier transform infrared spectroscopy （FT1R） and nuclear magnetic resonance spectroscopy （13CNMR and 1HNMR）. These instrumental analytical results agree with each other and further confirm the addition reaction pathway of glyoxal with urea proposed by quantum chemical calculation.

关 键 词：urea-glyoxal （UG） resin reaction mechanism synthesis MALDI-TOF FTIR NMR UV-vis 

分 类 号：O631.3[理学—高分子化学]