HBP—NH_2接枝氧化棉织物无盐染色机制

为揭示HBP—NH2接枝氧化棉织物(HGCF)实现活性染料无盐染色的机制,研究水溶液中HGCF纤维表面的zeta电位、HGCF活性染料染色热力学、染色动力学以及HGCF染色色光的变化等。结果表明:当pH<6.5时,在水溶液中HGCF纤维表面的zeta电位为正;HGCF对活性艳黄A-4GLN的吸附符合Langmuir模型,Langmuir吸附常数和饱和吸附量都随着温度的升高而降低,染色热为-4.51 kJ/mol;与未接枝棉织物相比,HBP—NH2对氧化棉织物的接枝改性可以加快上染速率,提高平衡上染百分率,增大表观扩散系数;HBP—NH2的接枝改性对棉织物活性染料无盐染色色光略有影响。

Mechanism of salt-free dyeing of HBP--NH2 grafted oxidized cotton fabrics

In order to reveal the mechanism of salt-free dyeing of HBP—NH_2 grafted oxidized cotton fabrics(HGCF) with reactive dyes,the ζ-potential of HGCF in the liquid phase,dyeing thermodynamics,dyeing dynamics and hue changes of HGCF dyed with reactive dyes were examined.As a result,the ζ-potential of the HGCF is positive at pH′s lower than 6.5.The dyeing behaviour of reactive brilliant yellow A-4GLN on HGCF was found to follow a Langmuir-type adsorption curve,and the value of adsorption constant and saturated adsorbing capacity decreased when the temperature was raised,the dyeing entropy is(-4.51 kJ/mol.) Compared to ungrafted cotton fabrics,HBP—NH_2 grafted oxidized cotton fabrics can improve the speed of dyeing,the equilibrium dye uptake and the diffusion coefficients.Meanwhile,there was slight hue changes on HGCF dyed with reactive dyes in salt-free dyeing.