制革生态化相关问题的研究—铬鞣剂的制备与应用

【作者】 程宝箴；

【导师】 张铭让；

【作者基本信息】 四川大学 ， 皮革化学与工程， 2002， 博士

【摘要】 鞣剂是用来处理生皮使之变成革的关键材料，与制革生态化有着密切的关系。在各种鞣剂中，鞣制效果最好的当属铬鞣剂，它有着其它鞣剂无法比拟的优越性能，在相当长的一段时间内，铬鞣法仍然是最主要的鞣制方法。 工业上制备铬鞣剂的传统方法有糖和二氧化硫两种还原方法。糖法生产的铬鞣剂虽然有一定的蒙囿作用，但在实际生产中，糖往往被氧化成极其复杂的中间产物，生产过程的不规律性使产品质量难以稳定，给鞣制带来一定的困难；而用SO₂作还原剂，虽然生产过程容易控制，产品质量稳定，但由于缺乏蒙囿性，用其鞣制的革比较扁薄。 针对以上两种还原方法的不足，本文以低碳醇为还原剂，研究了一种制备铬鞣剂的新方法。该方法具有意义重大的原始创新性。 本文系统地研究了多种小分子醇与重铬酸盐之间的氧化-还原反应，对反应过程进行了认真的剖析；对铬鞣液的干燥过程进行了研究；用红外光谱法、紫外及可见分光光度法、离子色谱法以及pH电位滴定法等多种比较成熟的现代分离分析方法相结合，对醇还原铬配合物的结构与性能进行了分析与表征；对铬鞣剂的鞣革性能进行了应用实验，研究了醇铬鞣剂在高pH值下的鞣制方法，并就高碱度铬鞣剂在制革过程中的应用进行了系统研究，探讨了用其实施清洁化铬鞣的可能性。 研究结果表明，选择适当的醇作还原剂，可制备出鞣革性能优异，利用率高的铬鞣剂，这对实现制革生态化是一个有力的促进。更多还原

【Abstract】 Tanning agent which converts skins or hides into leather is a chemical material having close relationship to ecology. Among all tanning agents, chrome tanning agent is the best one which has good performance that the others can not compete to it. hi a long time in the future, chrome tannage is still the most important tanning method.Two main ways in industry traditionally were used to prepare chrome tanning agents: one is using sugar as reducing agent, another is using sulfur dioxide. Chrome tanning agents prepared from sugar have some masking effect, but in fact sugar often is oxidized to very complicated middle outcomes in production process. This made qualities of the chrometan not stable and brought some trouble to tanning. When sulfur dioxide was used as reducing agent to produce chrome tanning agents, though production process is easily controlled and qualities of the product are stable, the tanning agent is lack of masking effect so that leather made with it is some tinny.To get over shortages of above tow reducing methods, a new preparation method is invented to produce chrome tanning agent in this paper, which is vitally important innovation.A systematic study was conducted to oxidation-reduction reaction of many kinds of small molecule alcohol with bichromate. A detailed analysis was conducted to reaction process. The drying process of chrome liquor was studied. The structure and property of chrome complex reducing by alcohol were analysed and tokened by many present well-rounded separation and analysis methods such as IR, UV-Vis Spectrum, IEC and pH potentiometry. Application tests of chrome tanning agents were conducted and tanning methods of tanning at high pH were studied. A systematic study was conducted on high alkalinity chrome tanning agents application in leather making process and possibility of clean chrome tanning was discussed.The results have indicated that chrome tanning agent with good tanning property and high utilization ratio can be gotten by selecting proper alcohol as reducing agents. This is a forceful promotion to tanning ecology.更多还原