Attapulgite's Modification And Its Application For Polymer Nanocomposites

In this dissertation, attapulgites′purification,pretreatment with acid (hydrochloric acid or acetic acid),modification by CTAB or KH570 or benzoyl chloride and nanocomposites′preparation (org-attapulgite/SBS nanocomposites and org-attapulgite/CA nanocomposites) and adsorption of arsenate were done.Fourier transform infrared spectroscopy (FT-IR) analysis,X-ray diffraction (XRD) analysis and SEM revealed quartzs almost disearpered which associated with the attapulgite minerals. SEM was used to show the morphology and the dispersion of the attapulgite nanorods which were purified by polyacrylic acid sodium (PAAS). The results appeared that the attapulgite minerals were longest and were most easily dispersed into solutions which were purified in water solutions with a PAAS content of 1wt% or 2wt%.Acid and salt pretreatment made attapulgite more easily be modified. All of the three organic compounds could make nanocomposites with better interface between orgattapulgite and polymers.Environmentally benign nanocomposites were synthesized using cellulose acetate (CA) and organically modified clay nanofillers for the first time. SEM disclosed that the nanorods were well separated and uniformly dispersed in the CA. There were many cavities within CA nanocomposites. The size of the cavities of CA nanocomposites could be controlled by the amount of the benzoyl chloride molecules been used to modify attapulgite nanorods. When 1ml of the benzoyl chloride molecules were used to modify 0.1 gramme of the attapultie nanorods. Nevertheless, no cavities were formed as 0.1 gramme of the nanorods qualified by 5 ml of the benzoyl chloride molecules.The thermoplastic elastomer SBS/AT nanocomposites were produced from SBS with org-attapulgite by solution method for the first time. The structre and morphology of the nanocomposites were charactered by SEM. The results reflected the nanofillers were uniform.With the addition of the content of attapulgite nanocrystals from 1wt% to5wt%, the tensile strength of these nanocomposited increased at first, then it decreased. Tensile strength reaches a maximum when the org-attapulgite contentis 3%, 30% increment compared with neat SBS.In this paper, the natural and modified attapulgite minerals were tested to remove arsenious acid negative ion from aqueous solution. The modified attapulgite were prepared by being activated with hydrochloric acid. Atomic fluorescence spectrum analysis recealed the maximum adsorption ratio of modified attapulgites in the isothermal adsorption test was 1.7 mg/g, twice of the maximum adsorption ratio. Only within 10 minute, the adsorption ratio reached 96% of the maximum.