淀粉基聚酯型耐水性木材胶粘剂

摘要

从高光效的谷物作物玉米中很容易分离出的淀粉适合作为绿色化学工业的可再牛原料.该文介绍一种聚酯型耐水性无甲醛玉米淀粉基木材胶粘剂制作工艺.该工艺包括了4个步骤:1)玉米淀粉硫酸固相氧化制备氧化淀粉;2)氧化淀粉常压快速液化制备高反应活性淀粉基多元醇;3)高活性淀粉基多元醇与等当鼍多兀酸(酸酐)混合和部分酯化交联;4)经过预酯化的产物用无水乙醇稀释使之成为可喷雾施胶的聚酯型木材胶粘剂.使用该新型木材胶粘剂所制备的杨木胶合板的胶合强度和耐水性能可以达到国标Ⅰ类板的要求.该文报道了硫酸的质量分数、氧化反应温度和时间;液化剂与氧化淀粉质量比、液化反应温度和时间、交联剂的羧基与多元醇羟基的当量比等加工工艺参数以及施胶量、热压温度、压力、热压时间等使用技术参数对用该种聚酯型木材胶粘剂制备的杨木胶合板的胶合强度和耐水性的影响.%Corn starch is one of the most adaptable and renewable industrial raw materials since it is abundant and easy to be separated. A process for manufacturing water resistant corn starch based and formaldehyde-free wood adhesive included four steps: corn starch was denatured by solid phase oxidation to produce oxidized corn strach. The oxidized corn starch was rapidly liquefied by ethylene glycol under ambient atmosphere at 110-140℃ to produce starch based polyoi with high reactivation. Then the starch based reactive polyol was crosslinked with equivalent multicarboxylic acid (anhydride) through the ester bond. And pre-polymerized polyester type wood adhesive was diluted by absolute ethanol to prepare the sprayable wood adhesive. The resulting adhesive performed well as a formaldehyde-free wood adhesive. Multi-ply wood composites bonded with this polyester type adhesive had acceptable shear strengths and water resistance.