催化剂对双氧水氧化淀粉-锆配合物结构及鞣制性能的影响

Effect of Catalyst on Structure of Hydrogen Peroxide Oxidized Starch and Its Performance as a Ligand in Zirconium Tanning of Leather

分别用钨酸盐、偏钒酸盐和铜-铁盐催化双氧水氧化淀粉,制得氧化淀粉配体,测定了氧化淀粉的氧化度和双氧水分解率,采用核磁共振碳谱、红外光谱和凝胶渗透色谱等分析了氧化淀粉的官能团结构和相对分子质量。考察了氧化淀粉-锆配合物的鞣制性能。铜-铁盐可催化葡萄糖单元C-2,C-3和C-6位的羟基氧化为羰基和羧基,同时打断α-1,4-糖苷键,制得低相对分子质量（14628）、高氧化度（72.5%）的氧化淀粉,用作配体可明显提高锆配合物在皮革中的分布均匀度（97.8%）和结合量（ZrO2质量分数8.0%）,皮革收缩温度达89.7℃,鞣制效果最佳。钨酸盐催化氧化淀粉的相对分子质量高（465095）,氧化度低（15.0%）,形成的锆配合物鞣制性能差。偏钒酸盐催化氧化淀粉的鞣制性能介于上述两者之间。

Oxidation of starch with hydrogen peroxide was catalyzed by tungstate, metavanadate and copper-iron salts, respectively. The oxidation degree of oxidized starch and the decomposition rate of hydrogen peroxide were determined. The functional groups and relative molecular weight of oxidized starch were characterized by ^（13） CNMR, FTIR, gel permeation chromatography（GPC） and so on. The tanning performance of oxidized starch as a ligand for zirconium tanning of leather was investigated. The hydroxyl groups at the positions C-2, C-3 and C-6 in the glucose unit were oxidized to carbonyl and carboxyl groups, and the α-1, 4-glycosidic bonds were broken during oxidation using cooper-iron salts as catalyst. Subsequently, the oxidized starch with a relatively low molecular weight（14628） and a high oxidation degree（72.5%） was used as a ligand of zirconium tanning agent. The Zr distribution（97.8%） and fixation [w（ZrO2）=8.0%]in leather were remarkably improved, and the shrinkage temperature of leather reached 89.7 ℃, leading to better tanning performances. Oxidized starch by using tungstate as catalyst had a higher molecular weight（465095） and a lower oxidation degree（15.0%）, and was poorer in tanning performances when it coordinated with zirconium salt. While, the tanning performances of oxidized starch obtained by using metavanadate as catalyst was between the above two kind of oxidized starch.