水在铬鞣、染色中的作用研究

Function of Water in Chromium Tanning and Dying Process

以超临界CO2流体和水作为介质,对比研究水在鞣革和染色过程中的作用。结果表明:在完全无水的超临界CO2流体中,铬鞣剂和染料渗透不均匀,结合量低、结合牢度差,鞣剂的鞣制效应差;少量水的存在,能增进铬鞣剂和染料的吸收率和结合牢度,铬鞣剂能发生原位水解配聚作用,成革收缩温度高;与水相中的铬鞣和染色相比,由于非极性CO2分子的离间作用,水的占位效应和竞争反应减弱,铬鞣剂和染料分子在超临界CO2流体中的渗透速度快,鞣制和染色时间缩短。

Supercritical CO2 fluid and water were used as medium separately, the function of water in chromium tanning and dying process was investigated. The results indicate that in CO2 supercritical fluid medium without water the penetration of chrome tanning agent and dyestuff is uneven, the maximum adsorption capacity （ Amax ） and combination fastness are low, and poor chro- mium tanning effect is obtained. But in CO2 supercritical fluid medium with some water the maximum adsorption capticity （An ） and combination fastness of chromium （ Ⅲ） and dyestuff are greatly increased. Due to the hydrolysis and multi - core - coordina- tion between chromium （Ⅲ ） and carboxyl groups of collagen in absence of water, the final leather shows higher shrinkage tempera- ture. Comparing to the chromium tanning and dying in water phase, the occupation effect and competitive effect are weaken be- cause of the de - association effect of non - polar COs molecular. As a result, the penetration rate of chrome tanning agent and dye- stuff is increased and the time of chromium tanning and dying is reduced.