耐水性大豆基木材胶粘剂两步法工艺研究

DEVELOPMENT OF A TWO STEPWISE PROCESSING ART OF WATER TOLERABLE SOY BASED WOOD ADHESIVE

利用天然高分子聚合物开发无甲醛木材胶粘剂是人类社会发展的必然选择。在国际上，利用低温大豆粕制备生物质基木材胶粘剂具有相当长的历史。但是在传统豆胶制备方法中，碱等变性剂用量高达豆粕干重的6％～7％或更高，外加4％左右的石灰乳。豆胶中残碱对大豆蛋白的水解破坏难以得到控制，因此传统豆胶都不属于耐水胶粘剂。在本研究中，采用低碱量低液比高强度变性和均质处理分两段进行的工艺技术解决了这一矛盾。得到了制备符合国标Ⅱ类（耐热水）的大豆基木材胶粘剂的主要工艺参数并通过验证试验加以确定。最后把新法豆胶优化工艺与两个典型的传统豆胶制作配方做了比较。这种豆胶制备新工艺具有国际先进水平。

In conventional process of preparing soy based wood adhesive, the dosage of alkali is often higher than 6%-7%（w/w） of the dry soy flour mass, adding on about 4% of lime milk. The alkalinity hydrolysis of soy protein caused by the residual alkali is always loss control and it is considered as the main reason of low water tolerance of soy based wood adhesive. In present investigation, a novel two stepwise process was adapted. Firstly half dosage of denaturants combined with low liquor ratio was used to create a high concentration circumstance tha was necessary for soy globulin unfolding; and in the second step, the lion share of water was mixed with the denatured soy flour that quickly dilute the alkali to keep the stability of unfolded soy protein. Water tolerable soy based wood adhesive was successfully manufactured by this novel processing art.