羧基对羟基酸脱铬性能的影响  

Study on the Influnence of Carboxyl Group on the Dechroming Performance of Hydroxy Acids

作　　者：杨春江[1] 田荟琳[1] 付丽红[1] 

机构地区：[1]齐鲁工业大学皮革化学与工程学院,山东济南250353

出　　处：《西部皮革》2016年第7期36-41,共6页West Leather

基　　金：国家级大学生创新创业训练计划(201510431025)

摘　　要：根据乳酸、苹果酸及柠檬酸脱铬过程中脱铬液pH值、铬含量和胶原水解量的变化,研究了羧基对羟基酸脱铬性能的影响。结果表明:羧基数多,脱铬量小,胶原水解轻,脱铬液平衡pH低;升高温度可减少位阻对脱铬的影响,高温短时有利于低元羧酸脱铬,高温长时有利多元羧酸脱铬;苹果酸和乳酸脱铬前期以H^+为主,柠檬酸脱铬与温度有关,低温以H^+为主,高温以酸根为主;胶原水解物对脱铬体系的pH值有缓冲作用,量越多,缓冲作用越大。The effects of carboxyl group on the dechroming performance were studied according to the changes of pH values and the amounts of chrome complexes and hydrolyzed collagen proteins in the dechroming solutions while using lactic acid, malic acid and citric acid. The results showed that with the increase of carboxyl groups, both the amounts of dechroming and hydrolyzed collagen proteins decreased and the final equilibrium pH values reduced. The effect of steric hindrance decreased with the increase of temperature. At high temperature, the short-time processing benefited the dechroming performance of monocarboxylic acid and the long-term treatment facilitated the dechroming of polycarboxylic acid. While dechroming,H~＋ has higher priority than lactic acid groups and malic acid groups at early stage of dechroming. As to citric acid, the reaction temperature had bigger positive impact on the dechroming and H~＋gave way to citric acid groups with the increase of temperature. The hydrolyzed collagen of dechroming solutions could constitute buffer system and the buffering effect was enhanced with the increase of amount of the hydrolyzed collagen.

关 键 词：乳酸 苹果酸 柠檬酸 脱铬性能 羟羧酸 

分 类 号：TS513[轻工技术与工程—皮革化学与工程]