一种封端聚氨酯助鞣剂的制备及性能  

Preparation and Performance of Blocked Waterborne Polyurethane

作　　者：田野[1] 刘洁[2] 

机构地区：[1]湖北轻工职业技术学院轻化工程学院,湖北武汉430070 [2]四川大学皮革化学与工程教育部重点实验室,四川成都610065

出　　处：《西部皮革》2014年第22期12-19,共8页West Leather

摘　　要：采用异佛尔酮二异氰酸酯（IPDI）、聚乙二醇（PEG-400）、二羟甲基丙酸（DMPA）为主要原料,以亚硫酸氢盐为封闭剂,合成了封端型水性聚氨酯（B-WPU）。通过红外光谱（FTIR）、纳米粒度仪及碘量分析分别对其结构、乳液粒径、封闭率进行了表征。用明胶做皮胶原模拟物,发现碱性条件下封端乳液与明胶反应后,明胶的黏度、总有机碳（TOC）均明显增加,而改性明胶膜的接触角变大,亲水性降低,表明B-WPU与明胶间发生了交联作用。将其作为一种预鞣剂直接用于脱灰软化皮的鞣制,收缩温度可提高至78℃;10%的封端乳液预鞣后再配合4%的铬粉鞣制,成革的收缩温度可达110℃。电感耦合（ICP-AES）测定表明,废液中的铬含量显著降低,铬的吸收率明显提高;与传统的铬鞣法相比,可省去浸酸操作时盐的加入,并有效降低30%-40%的铬粉使用量。In this paper, a blocked waterborne polyurethane（B-WPU） was synthesized through prepolymerization from isophorone diisocyanate（IPDI）, polyether polyols（PEG-400） and dimethylolpropionic acid（DMPA）, and subsequently blocked with Na HSO3. Structural properties, de-blocking temperature, particle size distribution, and blocking degree of synthetic product B-WPU were characterized and determined by FT-IR,DSC, Nano-ZS and iodimetric analysis respectively. Gelatin was used as a model of skin collagen, the chemical reaction between collagen and B-WPU under basic environment was investigated. Results showed that the Total Organic Carbon（TOC） and viscosity of modified gelatin were increased; meanwhile, the contact angle of modified gelatin film was increased, indicating decreased hydrophilicity. All of these revealed that the crosslinking reactions occurred between gelatin and B-WPU. After direct treatment of delimed and bated pelts with this B-WPU, the shrinkage temperature（TS） increased to approximately 78 ℃; pelts were pretreated with 10wt% WPU firstly and then followed by a 4% KMC chromium tannage, resulting in a high shrinkage temperature（-110 ℃）. Inductively coupled plasma-atomic emission spectrometry（ICP-AES） analysis showed that the chromium content of the effluent was decreased and the absorption of chromium was improved. In contrast with traditional chrome tanning, the chromium dosage decreased 30%-40%, and the addition of salts in the working step of pickling was omitted.

关 键 词：封端水性聚氨酯 明胶 鞣制 铬含量 

分 类 号：TS529.2[轻工技术与工程—皮革化学与工程]