氧化多糖-铝锆配合物鞣制技术的综合评价

Comprehensive evaluation of oxidized polysaccharide-Aluminum-Zirconium complex tanning technology

选用羧基含量和相对分子质量不同的氧化多糖配体OP1和OP2与铝盐、锆盐(AZ)进行配位鞣制,并与传统柠檬酸-铝锆(CA-AZ)鞣制和铬(Cr)鞣进行对比,评估了4种鞣制技术的鞣革性能、坯革性能和污染负荷。结果表明配体的相对分子质量对鞣制性能的影响比羧基含量大。重均相对分子质量7000左右的OP2同AZ形成的配合物鞣革收缩温度高(82.1℃)、阳电性强(等电点高于7.0),对染整材料的吸收率好(高于80%),使得坯革物性优良,仅次于铬坯革。相对分子质量较低的OP1(Mm;1000左右)和CA同AZ的配位鞣制性能不及OP2。此外,OP2-AZ鞣制废水的生物降解性优于CA-AZ和铬鞣废水。因此,氧化多糖-铝锆配合物鞣制技术有望成为一种实用、清洁的无铬皮革制造技术。

Oxidized polysaccharide ligands OP1 and OP2 with different carboxyl group contents and relative molecular weights were used to coordinate with aluminum salt and zirconium salt(AZ)for tanning.These two tanning technologies were compared with conventional citric acid(CA)-AZ tanning and chrome(Cr)tanning technologies in terms of the performance of tanned leather,the performance of crust leather and pollution loads.The results indicate that the relative molecular weight of the ligand has a greater influence on the tanning performance than that of carboxyl content.OP2 with Mw around 7000 was used as the ligand of AZ.Fhe tanned leather has high shrinkage temperature(81.2℃),strong positive electricity(isoelectric point higher than 7.0),and good absorption for post-tanning chemicals(more than 80%),thereby resulting in excellent physical properties of OP2-AZ crust leather,which is second only to chrome tanned crust leather.OP1(Mw around 1000)and CA with lower molecular weight show poorer tanning performance than OP2 when they coordinate with AZ.In addition,the biodegradability of wastewater from OP2-AZ tanning technology is better than that of wastewater from CA-AZ and Cr.Therefore,oxidized polysaccharide-aluminum-zirconium complex tanning technology is expected to become a practical and clean chrome-free tanning technology.