淀粉基木材胶黏剂的耐水性改性及表征

Water resistance modification and characterization of starch based wood adhesive

本文通过用酒石酸对玉米淀粉进行酯化处理制备酯化淀粉胶黏剂,然后用异氰酸酯对淀粉胶黏剂进行改性。讨论了反应温度和PVA用量对淀粉胶黏剂合成过程的影响,以及固含量和异氰酸酯对淀粉胶黏剂胶接强度和耐水性的影响。结果表明,反应温度为50~55℃,10%的PVA用量为淀粉量的15%时,胶液性能最佳;固含量为50%,加入少量异氰酸酯后,淀粉胶黏剂的胶接强度和耐水性有显著提高,达到杨木GB/T 9846—2004II类胶合板指标。采用差示扫描量热法（DSC）和热重分析仪（TGA）对异氰酸酯改性淀粉胶黏剂进行了表征,结果表明,异氰酸酯可以加快淀粉胶黏剂的固化速率,提高其热稳定性。

The esterified starch adhesive was prepared treated by esterification processing with tartaric acid on corn starch, and then the isocyanate was used to modifiy the starch adhesive. The influences of reaction temperature and PVA content on starch adhesive synthesis process were studied, as well as the effects of the solid content and isocyanates on the bonding strength and water resistance of starch adhesive were discussed. The results show that when the reaction temperature 50 ~ 55 ~C , PVA （10%） amount to be 15%, the adhesive properties was the best; the starch adhesive bonding strength and water resistance were improved signifcantly when the solid content to be 50%, adding a small amount of isocyanate, the treatment increased obviously bonding strength and water resistance, the products could meet the requirement of poplar wood GB/T9846-2004 II plywood. By adopting differential scanning calorimetry （ DSC ） and thermo gravimetric analysis （TGA）, the esterified starch adhesive with isocyanate were characterized. The findings show that isocyanates could accelerate the curing rate and improve the thermal stability of starch adhesive.