有机酸蒙囿铝（Ⅲ）配合物特性及与胶原反应性的研究

【作者】 丁克毅；

【导师】 张廷有；

【作者基本信息】 四川大学 ， 皮革化学与工程， 2001， 博士

【摘要】 应用pH滴定、反滴定以及Ferron计时比色法，从平衡态和动力学的角度，系统研究了有机酸蒙囿铝（Ⅲ）配合物溶液在有机酸盐种类和用量、铝盐种类、pH值及陈放时间等因素不同时，溶液中铝（Ⅲ）配合物的耐碱性、配聚性、酸降解性、存在形态及组份分布状况。通过GFC及LPIC等手段，分析了有机酸盐的种类和用量、铝盐的种类、pH值等因素不同时，溶液中铝（Ⅲ）配离子的大小及分布变化、有机酸根离子参与配位的情况，以及不同GFC分离流份中Al³⁺与参与配位的有机酸根离子浓度比值的变化规律。在此基础上，通过GFC分离制备及IR、²⁷Al NMR、XRD等方法，进一步研究了有机酸蒙囿铝（Ⅲ）配合物溶液的组成及组份结构，并通过皮粉鞣制实验考察了pH值、有机酸的用量等因素不同时，以及不同GFC分离流份中的铝（Ⅲ）配合物与皮胶原的反应特性。主要结论有： （1）有机酸蒙囿铝（Ⅲ）配合物在溶液中主要有3种存在形态，它们在8hs左右基本达到动态平衡，即：单核铝（Ⅲ）配离子2-4核低聚配离子“Al₁₃族”配离子。 （2）在与实际铝鞣相近的溶液环境中，铝（Ⅲ）配离子主要以“Al₁₃族”多核离子的形态存在，这是一类由N个（N大约在9～30范围内）八面体铝（Ⅲ）配离子围绕1个[AlO₄]^5-四面体配离子，通过共用1个或2个氧配原子而形成的具有刚性结构的球状离子团，随Al³⁺数目的不同，其直径约在8～16范围内变化。 （3）在有机酸蒙囿的铝（Ⅲ）配合物溶液中，参与配位的有机酸根离子只占加入量的少部分或极少部分，这与溶液中铝（Ⅲ）的主要存在形态——“Al₁₃族”配离子特殊的结构密切相关。溶液中铝（Ⅲ）配离子的存在形态及组成分布主要受pH值的影响，且在pH=3～4之间有一突变点。有机酸根离子的作用主要在于它们参与配位后，能一定程度上阻止鞣液中“Al₁₃族”配离子在pH值升高时进一步配聚，而在低pH值条件下又更易降解。 （4）有机酸蒙囿的铝（Ⅲ）配合物与胶原的反应性既具有金属鞣革配合物的通性，又具有其自身的特点。这也是由于铝（Ⅲ）配合物在溶液中的主要存在方式—“Al₁₃族”多核配离子的特性决定的。了解了鞣液中铝（Ⅲ）配合物的存在形态及组成分布在各种不同溶液条件下的变化规律之后，就不仅可以对铝（Ⅲ）配合物与胶原反应过程中的各种实验结果作出比较合理的解释，而且为进一步研究铝鞣及铝结合鞣的机理奠定了基础。更多还原

【Abstract】 From the aspects of equilibrium state and dynamics, pH potential titration,anti - potential titration and Ferron time - analysis were applied to research the characteristics of organic acid masked aluminum complexes solutions systematically, including alkli - resistence, poly - coordination , acid - decomposition, exsisting states and composition distributions, when the solution conditions such as the kinds of organic acid salts and their dose, kinds of aluminum salts,pH value of solutions and storage time were varied.Gel filter chromatography (GFC) and low pressure ion chromatography (LPIC) were applied to analyze the changing laws of aluminum complexes’ size, composition distribution and the coordination of organic acid anions with Al3+ nucleus, varying with the solution conditions such as kinds of organic acid salts and their dose, kinds of aluminum salts and pH values; the changing laws of the ratio between the concentrations of aluminum(Ⅲ) and organic acid anions binding with A13+ necleus in different GFC fractions were studied also. Moreover, GFC preparation method and IR,27Al NMR,XRD were used to research the composition distributions and the structures of organic acid masked aluminum complexes in solutions, and the reaction properties of complexes to collagen with different tanning pH values,different dose of organic acid salts and different GFC fractions. The main conclusions were:(1) Organic acid masked aluminum complexes were active complexes which existed in three different states in solutions and could reach equilibrium state within 8 hours or so, i. e.:mono - nuclear complexes ---- 2 - 4 nucleus polymeric complexes ----"Al13 like" complexes(2) In the solution conditions similar to aluminum tanning practice, the main exsisting state of aluminum complexes was "Al13 like" complexes, which had a stiff sphere structure constructed by one [AlO4]5- tetrahedron arrounded with N(N≈9- 30) octahedral aluminum complexes by means of "mono - oxygen - bridge" or "di - oxygen - bridge". Their diameters were 8 - 16A or so.(3) In organic acid masked aluminum complexes solutions, most or almost of the adding organic acid anions were in "free" state and did not coordinate with A13 + necleus. This result was closely related to the special structure of "Al13 like" complexes. The existing states and composition distributions of aluminum complexes were mainly influenced by pH values of the solutions. The test results indicated that there was a mutation point between pH = 3 - 4. The masking function of coordinating organic acid anions mainly lay on their preventing "Al13 like" complexes to further polymerize with other aluminum(Ⅲ) complexes when the pH value rised, and the "Al13 like" complexes could be easily decomposed in lower pH value solutions, i. e. , the coordinating organic acid anions endow the "Al13 like" complexes with the property of "alkli - resistant and acid - senstive".(4) The reaction property of organic acid masked aluminum (Ⅲ) complexes with collagen not only had the common feature of metal tanning complexes, but had its own characteristics also. This was determined by the characteristics of "Al13 like" complexes - the main exsisting state of aluminum (Ⅲ) complexes in solutions. Having known the changing laws of the exsisting states and composition distributions of aluminum complexes in different solution condutions, a rational explanation for many experiment results of aluminum tanning process could be given, a foundation for the mechanistic study of aluminum tanning and aluminum cooperating- tanning was laid also.更多还原