木材粘接用交联大豆蛋白胶的研究

以氢氧化钠改性脱脂大豆蛋白粉为基础胶,选用六次甲基四胺(HMTA)作为交联剂,制备了聚乙烯醇(PVA)改性的大豆蛋白胶黏剂。通过正交试验方法研究了HMTA用量、PVA溶液用量(PVA质量百分比浓度为12%)、热压温度、热压时间对粘接性能的影响;并用红外和热失重分析仪探讨了大豆蛋白胶的粘接机理。结果表明:当HMTA质量百分比用量为6.5%,热压温度为140℃,热压时间为10 min,大豆蛋白胶黏剂粘接性能较优;120℃加热1 h后,酰胺Ⅰ带和酰胺Ⅱ带红外特征峰朝高波数方向移动,表明高温下蛋白质胶内部的氢键数目减少;而属于HMTA的C-N的红外响应峰(1 236和1 007 cm~(-1))减小。研究结果表明HMTA参与了化学交联反应,HMTA的加入能提高大豆蛋白胶黏剂的耐热性能。

Studies of Crosslinked Soybean Protein Adhesive for Wood

A base glue was prepared by sodium hydroxide modified defatted soy protein powder,based on the base glue,the modified soybean protein adhesive for plywood was prepared with PVA solution,and hexamethylenetetramine as chemical crosslinker.The effects of HMTA usage,PVA solution amount(PVA mass percentage concentration 12％),hot pressing temperature and hot pressing time on adhesive properties were studied by orthogonal test.Structure and heat resistance of soybean protein adhesive were characterized by both FT-IR and TGA.The results showed that the soybean protein adhesive had relatively good adhesion properties with the usage of HMTA,the hot pressing temperature and the hot pressed time was 6.5％,140℃ and 10 min respectively.After the sample was heated at 120℃ for 1 h,the infrared bands of amide Ⅰ band and amide Ⅱ band move towards high wave number.The results showed that the number of hydrogen bonds in the protein decreased at high temperature,the peaks of 1 236 and 1 007 cm-1 attributed to C-N of HMTA got smaller.The results meant HMTA was involved in the chemical crosslinking reaction and the usage of HMTA can improve the heat resistance of soy protein adhesive.