Abstract: Cationic polyacrylamide with quaternary ammonium group was used for cotton pretreatment with dip-pad-bake method and the obtained cotton was applied to salt-free dyeing of reactive dyes. The adsorption behaviors of C.I. Reactive Red 195，C.I. Reactive Red 19 and C.I. Reactive Yellow 145 on cationised cotton were investigated. Langmuir and Freundich adsorption models were applied to describe the equilibrium isotherms and isotherm constants were obtained. Langmuir-type adsorption isotherms were determined for reactive dyes on cationised cotton and the pseudo-second-order model provided a very good fitting for the three reactive dyes. The thermodynamic parameters including change in free energy（ΔG），enthalpy（ΔH），and entropy（ΔS）were also calculated and discussed. The color yield and fastness properties of the dyes on both fibers were also investigated and the satisfactory results showed the feasibility of the pretreatment method.

摘要： 以季铵型阳离子聚丙烯酰胺作为一种新的阳离子助剂对棉纤维进行处理，应用于活性染料无盐染色，对染色过程中染料与处理后棉纤维之间的吸附类型、吸附热力学及吸附动力学进行了研究。结果表明，无盐染色过程符合Langmuir吸附模型；吸附过程是放热自发进行的，低温有利于染料的吸附；吸附动力学符合二级动力学模型，属于化学吸附过程。与传统有盐染色结果相比，染色后的阳离子化棉纤维色深增加，染料利用率提高。