钨酸在氧化淀粉制备中的催化作用研究

Preparation of Oxidized Starch with Tungstic Acid as Catalyst

采用钨酸作催化剂、双氧水作氧化剂制备氧化淀粉,通过与不加催化剂双氧水氧化淀粉比较,发现羧基含量增加、黏度下降明显,证明钨酸对双氧水氧化淀粉有催化作用,并与硫酸铜、硫酸亚铁等成熟的氧化淀粉催化剂进行比较,发现钨酸对氧化淀粉的制备有催化作用,并且具有催化作用比较温和、氧化深度比较均匀、色泽较好等特点。分析了pH值、反应温度、催化剂钨酸加入量对钨酸催化制备氧化淀粉的氧化深度的影响,确定了钨酸催化制备氧化淀粉的较优工艺。

By using tungstic acid as catalyst and hydrogen peroxide as oxidant, oxidized starch was prepared. A comparison with the oxidized starch preparation without catalyst and a comparison between the catalyst effects of tungstic acid and other catalysts such as copper sulphate, ferrous sulphate, etc. were carried out. Results： The carboxyl content in the oxidized starch catalyzed by tungstic acid increases, and product viscosity decreases significantly, indicating that tungstic acid has catalytic effect on the oxidized starch preparation. Compared with conventional catalysts such as copper sulphate, ferrous sulphate, etc. , the tungstic acid exhibits more moderate catalysis, more uniform oxidation degree, as well as better color identification. The effects of pH, reaction temperature, and tungstic acid dose on the oxidation degree of oxidized starch were systematically studied, and a proper preparation procedure of oxidized starch by using catalyst tungstic acid was established.