Application And Research Of Polymer Materials In The Preparation Of Water Treatment Agent

Water shortage is a major problem related to the national economy and people’s livelihood. Sewage treatment is an effective way to solve environmental pollution. At present, the composition of the water pollution is complex. Generally, water treatment can be divided into three steps. This paper mainly studied a cationic starch modified flocculant and P-cyclodextrin/polyacrylonitrile (PAN) nanofibers which can be used for secondary and tertiary steps. Characterized and discussed the influencing factors of materials preparation and their water treatment performance. The main contents include the following three aspects:(1) The effects of initiator concentration, reaction temperature, monomer ratio, reaction time, urea quantity and cationic conditions on graft polymerization were investigated. The optimal synthesis conditions:grafting temperature50℃, grafting time3h, mass ratio of starch and acrylamide1:3.2, initiator concentration0.9x10-3g/L, urea quantity2.5g, Molar ratio of acrylamide, dimethylamine and formaldehyde1:1:1.2, cationic temperature65℃, cationic time2h. The structure and characteristic of product was characterized by means of FTIR, SEM and TGA. The results show that polymer is the graft copolymer of starch and acrylamide and the difference between the graft copolymer and starch.(2) Using of different mass fraction of nano-Fe2O3dispersed in the spinning solution, nano-ferric oxide/β-cyclodextrin/polyacrylonitrile (Fe2O3/β-CD/PAN) nanofibers were prepared by electrospinning. Then, etched Fe2O3/β-CD/PAN nanofibers were obtained by etching out Fe2O3on the nanofibers’surface with HC1dilute solution. In addition, the morphology, thermal stability, rheology, BET surface areas and adsorption capacity on MB of Fe2O3/β-CD/PAN nanofibers were studied. The results showed that after etching out Fe2O3on the nanofibers’ surface, the diameter of etched10wt%Fe2O3/β-CD/PAN nanofibers was the best uniform which had obvious porous structure on the surface. The etched10wt%Fe2O3/β-CD/PAN nanofibers’ BET surface areas was reached25.63m2/g, this resulted in increasing adsorption sites of nanofibers’ surface for dye molecules. What’s more, the heat resistance and conductivity of electrospining solution were improved by filling Fe2O3nanoparticles. The equilibrium adsorption amount of etched10wt%Fe2O3/β-CD/PAN nanofibers on MB was7.99mg/g enhanced50.471%compared with (3-CD/PAN nanofibers.(3) Epichlorohydrin as the cross-linking agent was used to get β-cyclodextrin cross-linked polymer (β-CDP), and β-CDP/PAN nanofibers were prepared by electrospinning. The viscosity of electrospinning solution and the morphology, structure, adsorption properties on MB of nanofibers were characterized by field emission scanning electronmicroscope (FE-SEM), infrared spectroscopy (FT-IR), ultraviolet-visible spectrophotometer (UV) and rotational rheometer. The results showed that much "bulge-like" structures were appeared on β-CDP/PAN nanofibers’surface, and this resulted in increasing adsorption sites of nanofibers’ surface for dye molecules. Better morphology of composite nanofibers could be prepared by controlling of the weight percent of β-CDP and30wt%β-CDP/PAN nanofibers were the best uniform. The equilibrium adsorption amount of30wt%β-CDP/PAN nanofibers on MB was10.84mg/g enhanced104.143%compared with β-CD/PAN nanofibers. In addition, p-CDP/PAN nanofibers’adsorption kinetics on MB was accorded with the second-order equation and isotherm adsorption was corresponded with the Langmuir adsorption isotherm. The maximum adsorption capacity was14.035mg/g (35℃, CDP-30/PAN0.667g/L, MB2x10-5mol/L). Also, the adsorption was an endothermic process and could happen spontaneously.