碱性蛋白酶改性大豆蛋白胶黏剂的研究

Study on Alkaline Protease Modified Soybean Protein Adhesive

为解决大豆蛋白胶黏剂相对分子量高、黏度大以及改性剂用量多等问题,需要制备一种由碱性蛋白酶改性的新型大豆蛋白胶黏剂,使其满足室内使用胶合板及胶合制品的要求。本研究以脱脂大豆蛋白粉为主要研究对象,碱性蛋白酶作为改性剂,探究不同酶添加量、pH、酶解温度、酶解时间对大豆蛋白胶黏剂胶合强度的影响,并通过正交试验对其工艺条件进行优化。结果表明:大豆蛋白胶黏剂适宜反应条件为碱性蛋白酶添加量10 000 U·g^(-1)、pH9.5、酶解温度60℃、酶解时间100 min。改性胶黏剂与未改性的大豆蛋白胶黏剂相比,黏度由2 400 s降低为13 s,胶合强度由0.74 MPa提高为0.98 MPa,符合国家标准GB/T 9846—2004Ⅱ类胶合板要求。试验表明碱性蛋白酶改性大豆蛋白胶黏剂在胶合板生产领域中具有良好的应用前景。

In order to solve the problems of low bonding strength and high viscosity of soybean protein adhesive and toxic volatile substances such as formaldehyde in the adhesive,a new type of green soybean protein adhesive was prepared to meet the requirements of indoor use of plywood and glued products.In this study,defatted soybean protein powder was taken as the main research object,and alkaline protease was used as the modifier to explore the effects of different enzyme additions,pH,enzymolysis temperature,and enzymolysis time on the bonding strength of soybean protein adhesive.The optimum reaction conditions of soybean protein adhesive were obtained through orthogonal design experiment enzymolysis as followos:alkaline protease 10000 U·g-1,pH9.5,temperature 60℃and time 100 min.Compared with unmodified soybean protein adhesive,the viscosity of modified adhesive decreased from 2400 s to 13 s,and the bonding strength was increased from 0.74 to 0.98 MPa,meeting the requirements of the national standard GB/T 9846-2004 Class II plywood.The experiment shows that the alkaline protease modified soybean protein adhesive has a good application prospect in the field of plywood production.