Synthesis And Application Of Polyurethane High Molecular Acid Leather Dyes

Because of their outstanding environmental performance applications and excellent comprehensive performance, waterborne polyurethane and polymer dye, applications involving gradually expanded. The article summarizes the two materials, introduced their synthesis method and application performance and then taking into account its comprehensive application, synthetic a waterborne polyurethane polymer dye, combining with the consistency of the two materials synthesis applications. And applied them to leather dyeing process and finishing processes.Investigated their characteristics and the effect application.In this research, first of all, TDI and PPG-1000 as the raw materials are synthesized into polyurethane prepolymer. Then use DMPA synthesis polyurethane which is both ending with-NCO groups, modified it by-OH groups dye(C.I. Acid Red 14, Acid Black 31 and Acid Yellow 11) to make macromolecule polyurethane dye. Adjust synthesis parameters prepared two series of polyurethane polymer dye, respectively applied in leather dyeing process(referred PUⅠ- Acid Red B, PUⅠ- Acid Yellow G and PUⅠ- weakly acidic black BG) and leather finishing process(referred PUⅡ- Acid Red B, PUⅡ- Acid Yellow G and PUⅡ- weakly acidic black BG).In the preparation process, initiation polymerization was confirmed as the optimum experimental parameters n(-OH): n(-NCO) = 1: 3 ~ 1: 4, added with the DMPA and blocked with dye and the control system total R value is 1.1~1.2.Characterization and Studying on the product and film properties by the chief means of infrared spectroscopy, laser particle size analysis, color fastness testing and thermodynamic Analysis. The results show that: Aqueous polyurethane polymer combine dye by an amide bond(-CO-NH-) connected, is stable and the average particle diameter is 60 ~ 160μm. Which to meet the requirements of the aqueous medium dyeing.In modified polyurethane dye series PU-Ⅰ as research subject, use leather shaving to simulate wet blue leather blank, do dyeing experiment and compared with the corresponding single small molecule. The results show that: small molecule dye uptake rate between 68 %~78 %, fixation rate between 81 % to 87 %; mean while, polyurethane polymer dye rate between 92 %~98 % fixation rate up to 93 % above.According to infrared characterizing these dander Before and after dyeing, studied the dyeing mechanism when polyurethane modified dye on the leather fibers. Chemical analysis shows that the-COOH groups of polyurethane polymer dye combine with the chrome in Chrome tanned leather in coordinate bond. Also exist-COOH groups combine with the-NH2 groups of tanned leather fibers in ionic Bond. The two main forces between molecules connects some cross-linking between the leather fibers, finally apparent covalent bond combined with leather fibers to dyes.In modified polyurethane dye series PU-Ⅱ as research subject, in the finishing process using Polyurethane dye instead of the dye water making coating to detect. The results show that: coating dry friction color fastness reached 5 level, wet wiping color fastness more than 4.5 standard, migration resistance more than 4 standard, Resistant to organic solvents, dry heat-resistant color fastness reach 4.5 level; hot mobility and thermal mobility of colored polyurethane coating from 0.4 % to 1.02 %. Also confirmed this polymer acid dyes have good color fastness, excellent performance in the finishing process.