Liang Jiankun, Wu Zhigang, Lei Hong, Xi Xuedong, Li Taohong, Du Guanben
Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products, Southwest Forestry University, Kunming 650224, China.
Material Science and Technology College, Beijing Forestry University, Beijing 100083, China.
Polymers (Basel). 2017 Dec 14;9(12):711. doi: 10.3390/polym9120711.
To guide the preparation of protein-based adhesive, especially the soy-based adhesive, the reaction between a simple dipeptide -(2)-l-alanyl-l-glutamine (AG), being used as a model compound of protein, and its cross-linker furfuryl alcohol were studied in this paper. The products that were prepared with furfuryl alcohol and AG under different pHs were analyzed by ESI-MS, C NMR, and FT-IR. It was found that the medium environment had great effects on the competition of the co-condensation reaction between furfuryl alcohol and AG and self-condensation reaction of furfuryl alcohol molecules in the mixing system with furfuryl alcohol and AG. Under alkaline conditions, both co- and self-condensation were not obviously detected. Only when the value of pH was higher than 11, were a few co-condensation reaction products gotten. The reaction occurred mainly between furfuryl alcohol and the primary amido groups of AG. Under acid conditions, both co- and self-condensation were observed. The more acid the preparation conditions were, the easier to be observed the self-condensation of furfuryl alcohol molecules would be than the co-condensation between furfuryl alcohol and AG. When the value of pH was higher than 5, both co- and self-condensation were not outstanding. In this study, under pH 3, the co- and self-condensation found equilibrium. There was a great possibility for the primary amido and aliphatic amino groups of AG molecules to react with furfuryl alcohol molecules. No reaction was detected between the secondary amido groups of AG and furfuryl alcohol.
为指导基于蛋白质的粘合剂尤其是大豆基粘合剂的制备，本文研究了用作蛋白质模型化合物的简单二肽-(2)-L-丙氨酰-L-谷氨酰胺（AG）与其交联剂糠醇之间的反应。用糠醇和AG在不同pH值下制备的产物通过电喷雾电离质谱（ESI-MS）、碳核磁共振（C NMR）和傅里叶变换红外光谱（FT-IR）进行分析。发现介质环境对糠醇与AG的共缩合反应以及糠醇与AG混合体系中糠醇分子的自缩合反应的竞争有很大影响。在碱性条件下，未明显检测到共缩合和自缩合。只有当pH值高于11时，才得到少量共缩合反应产物。反应主要发生在糠醇与AG的伯酰胺基之间。在酸性条件下，观察到了共缩合和自缩合。制备条件酸性越强，糠醇分子的自缩合比糠醇与AG的共缩合越容易观察到。当pH值高于5时，共缩合和自缩合都不显著。在本研究中，在pH 3时，共缩合和自缩合达到平衡。AG分子的伯酰胺基和脂肪族氨基与糠醇分子反应的可能性很大。未检测到AG的仲酰胺基与糠醇之间的反应。
