A combination chrome tanning technology which endows leather high chrome exhaustion and thermal property based on hydroxyl-terminated dendrimer (HTD) is reported. The chrome concentration in effluent, denaturation temperature (Td), enthalpy (ΔH), thermal degradation active energy (Ea), crosslinking degree of wet-blue leathers are determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES), differential scanning calorimetry (DSC), thermal gravimetry analysis (TG-DTG), and X-ray diffraction (XRD), respectively. The element (especially chromium) content and distribution of wet-blue leather are also obtained by scanning electron microscopy-energy dispersive spectrometer (SEM-EDS). The results show that the chrome uptake, Td, ΔH and Ea of wet-blue leather tanned with HTD and basic chrome sulphate (HTD-Cr) can reach 94.1%, 117.4 °C and 432.2 J/g, and 153.1 kJ/mol much higher than conventional chrome tanning which is 66.1%, 112.5 °C and 129.2 J/g and 147.2 kJ/mol, respectively. It is because HTD could act as excellent masking agent with good alkaline stability, which slows down the basifying process and promotes chrome penetration towards central of wet-blue leather, resulting in evenly dispersed along the grain layer, middle layer and flesh layer of wet-blue leather. Consequently, crosslinking density of collagen increased, thereby inhibiting the outward diffusion of chrome and improving the chrome uptake. In contrast, for blank trial, the chrome mainly aggregate at grain layer and flesh layer. These results illustrate the chrome tanning promotion mechanism of HTD and provide a valuable insight of developing high exhausted chrome agent based on dendrimer for more sustainable future of leather industry.

据报道，基于羟基封端的树枝状大分子（HTD）的组合铬鞣制技术可赋予皮​​革高铬耗竭性和热性能。通过电感耦合等离子体原子发射光谱法（ICP-AES），差示扫描量热法测定废水中的铬浓度，变性温度（Td），焓（ΔH），热降解活性能（Ea），湿蓝色皮革的交联度。 （DSC），热重分析（TG-DTG）和X射线衍射（XRD）。湿蓝色皮革的元素（尤其是铬）含量和分布也可以通过扫描电子显微镜-能量色散光谱仪（SEM-EDS）获得。结果表明，用HTD和碱性硫酸铬（HTD-Cr）鞣制的湿蓝色皮革的铬吸收率，Td，ΔH和Ea可以达到94.1％，117。分别比传统的铬鞣制革分别高6°C，66.1％，112.5°C和129.2 J / g和147.2 kJ / mol，分别高4°C和432.2 J / g和153.1 kJ / mol。这是因为HTD可以用作具有优良碱性稳定性的出色掩蔽剂，从而减慢碱化过程并促进铬向湿蓝色皮革中央渗透，从而使湿润皮革的颗粒层，中间层和果肉层均匀分散。蓝色皮革。因此，胶原的交联密度增加，从而抑制了铬的向外扩散并改善了铬的吸收。相反，对于空白试验，铬主要聚集在谷物层和果肉层。