NaClO用量对氧化-酯化改性淀粉胶黏剂性能的影响

Effect of NaClO Dosage on Properties of Oxidation-Esterification Modified Starch Adhesive

以木薯淀粉为主要原料,采用次氯酸钠为氧化剂成功制备氧化-酯化淀粉胶黏剂,利用异氰酸酯作为交联剂,压制胶合板。讨论了氧化剂的用量对淀粉胶黏剂的黏度、固体质量分数及胶合强度的影响,并通过傅里叶红外、热重分析仪和扫描电镜等方法对氧化改性淀粉胶黏剂的化学结构、热稳定性和微观结构进行系统分析。研究结果表明:次氯酸钠氧化木薯淀粉后能够显著提升淀粉胶液的流动性,最佳添加比例10%时,淀粉胶黏剂黏度为4230 mPa·s,固体质量分数为29.83%,胶合板的湿强度以及水煮强度可分别达到1.05和0.81 MPa,均满足国家Ⅱ类板标准(GB/T 9846.3-2015)。

With cassava starch as the main raw material,we used sodium hypochlorite as oxidant to successfully prepare oxidized-esterified starch adhesive,and used isocyanate as cross-linking agent to press plywood.The effects of oxidant dosage on viscosity,solid content and bonding strength of starch adhesive were discussed.The chemical structure,thermal stability and microstructure of oxidized modified starch adhesive were systematically analyzed by Fourier transform infrared spectroscopy,thermogravimetric analysis and scanning electron microscopy.The sodium hypochlorite oxidation of cassava starch can significantly improve the fluidity of starch glue solution.When the optimal addition ratio is 10%,the starch adhesive is 4230 mPa·s,and the solid content is 29.83%.The wet strength and boiling strength of plywood can reach 1.05 and 0.81 MPa,respectively,which meet the national Class II board standard(GB/T 9846.3-2015).