Preparation Of Ion Exchange Fiber From Waste Natural Cotton Fiber And Properties Research

Cotton is used in industry,agriculture,medical,national defense and daily life of the people,and extremely wide range of applications.The use of cotton will produce a lot of wastes,and the main waste disposal are burying and burning or other methods that are not friendly to the environment,and not only will cause a lot of waste of resources,will also cause the pollution of air and land.Therefore,the resource recycling of waste cotton fiber is the very vital significance.Based on the summary of research and application technology of ion exchange fiber and the processing of waste cotton fiber.it focuses on the principle of preparing ion exchange fiber from waste natural cotton fiber and find a method for preparing ion exchange fiber by grafting modification of cotton fiber.The waste cotton in Jianghan Plain was used as raw material in this paper,The ion exchange material?CED?with adsorption function was prepared by activation of waste cotton fiber and step-by-step grafing reaction,with epichlorohydrin?Ep?and diethylene triamine?DT?as graft monomer.The main factors affecting the performance of products were investigated by single factor optimization experiment,and the adsorption kinetics of ion exchange fiber?CED?was also studied.The main research contents and conclusions are as follows:The NaOH solution was used to activate the waste cotton fiber,and the results of XRD test showed that the crystallinity and grain size of the cotton fiber were decreased after activation.The ion exchange fiber?CED?was prepared by graft modification of epichlorohydrin?Ep?and diethylene triamine?DT?as grafting monomers.The morphology and structure of the samples were characterized by the SEM and FT-IR,The SEM and FT-IR result indicates that the surface of waste cotton fiber becomes rough after treatment,and a large amount of granular or fluffy material is attached to the surface;the corresponding active groups were introduced onto the molecular structure of cotton fiber.Result shows that the molecular structure and apparent morphology of cotton fiber were changed by grafting modification,the epichlorohydrin?Ep?and diethylene triamine?DT?were successfully grafted onto thewaste cotton fiber.Through the analysis of single factor experiments,the optimum process conditions of epoxy cotton fiber?CE?are that : activated cotton fiber was 3g,epichlorohydrin?Ep?was 30 mL,absolute ethanol was 10 mL,8% NaOH aqueous solution was 150 mL,grafting temperature was 70?,grafting time was 8h.the epoxy value of epoxy cotton fiber?CE?that was prepared can reach 1.15 or more on the condition.The optimum process conditions for the ion exchange fiber?CED?are that:Dry epoxy cotton fiber was 3.5g,Deionized water was 100 mL,Na2CO3 1.5g,diethylene triamine?ED?was 8.0g,Under the condition of nitrogen protection,the grafting temperature was 55 ?,and the grafting time was 3h.Under the certain condition,the adsorption capacity of Cu²⁺ and Ni²⁺ could reach the maximum value.Study on the adsorption properties of Cu²⁺ and Ni²⁺ by ion exchange fiber?CED?showed that the pH of 3-4,the temperature of 35?,the adsorption time of 60 min,the initial concentration of Cu²⁺ is 500 mg/L,on exchange fibers have the maximum adsorption capacity of Cu²⁺,it can be reached 334.56mg/g;pH of 3-4,the temperature of 35?,the adsorption time of 40 min,the initial concentration of Ni²⁺ is500 mg/L,on exchange fibers have the maximum adsorption capacity of Ni²⁺,it can be reached 334.56mg/g.The adsorption kinetics of Cu²⁺ and Ni²⁺ were found,the ion exchange fiber adsorption?CED?Cu²⁺ and Ni²⁺ conform to adsorption model of monomolecular layer,and the adsorption process conforms to the Langmuir adsorption isotherm model.By model linear fitting,the correlation coefficient R2 is more than 0.99.The adsorption kinetic follows the laws of qseudo-second order kinetic model,and the correlation coefficient R2 is more than 0.99.The apparent activation energy to Cu²⁺was 1.829 KJ /mol and the pre-exponential fact was 0.000235.The apparent activation energy to Ni²⁺ was 4.036 KJ /mol and the pre-exponential fact was 0.00093.