以普通酚醛树脂(PF)和戊二醛改性的酚醛树脂(PFG)作为大豆蛋白胶粘剂的改性剂.研究结果表明:PF和PFG都能显著提高大豆蛋白胶粘剂的胶合强度和耐水性能,后者具有较低的游离甲醛和游离苯酚,是一种相对环保的酚醛树脂,更适宜做大豆蛋白胶粘剂的改性剂.2者具有类似的主体结构,后者由于具有较高韧性使其改性的大豆蛋白胶粘剂具有较高的机械强度和耐水性,但改性后大豆蛋白胶粘剂的固化温度高于PF改性后的大豆蛋白胶粘剂的固化温度.模型化合物反应表明酚醛树脂改性大豆蛋白胶粘剂时,发生共缩聚反应的位点更可能发生在蛋白质的支链型氨基上.
The soy protein-based wood adhesive crosslinked with common phenol formaldehyde resin PF) and phenol formaldehyde resin modified with glutaraldehyde (PFG) was studied in this paper.The results showed that the bonding performance and water resistance of the soy protein-based adhesive were improved greatly by adding PE and PFG.There are lower contents of free formaldehyde and free phenol in the PFG resin than those of the PF resin.Herein,the PFG resin is an environmentally friendly crosslinker,which is more suitable to modify the soy protein-based adhesive.The PF resin and PFG resin have the similar body structures,but the latter one provided higher mechanical strength and water resistance of the modified adhesive due to its high toughness.However,the curing temperature of soy protein-based adhesive crosslinked with PFG was higher than that for PF.The model compound reactions showed that the site of the copolycondensation reaction of phenolic resin modified soy protein adhesive is more likely on the branched amino group of the protein