Synthesis Of Aza-crown Ether/Cyclodextrin Modified Chitosan And Their Properties

Chitin and chitosan are renewable and abundant natural macromolecule compounds, which are nontoxic, biocompatible and biodegradable.These biopolymers could be used as macromolecular sorbents. The structure, physical-chemistry properties and relevant chemical reaction of chitin and chitosan were reviewed; The adsorption properties of chitin, chitosan and their derivatives for metal ions their applications were introduced. And the properties and application in environmental science of crown ethers, polymerized crown ethers and Cyclodextrin Containing Polymer were reviewed in this paper.Two novel chitosan immobilization of β -cyclodextrin sorbents and four novel aza-crown ethers chitosan were synthesized. The structure of these sorbents were confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD). The adsorption properties of sorbents for heavy metal ions and organic compounds were studied.The main contents and conclusions are described as follows:(1) Two novel chitosan immobilization of β -cyclodextrin sorbents were synthesized by the reaction of β -cyclodextrin with epoxy-activated chitosan and sulfonation of C-6 hydroxyl group of β-cyclodextrin with chitosan. Their structures were confirmed by infrared spectra analysis, X-ray diffraction analysis and the apparent amount of grafting of them were determined by UV. The adsorption properties of these for p-dihydroxybenzene were studied. The experimental results showed that the two new adsorbents exerted adsorption upon the carefully chosen target. The highest saturated capacity of p-dihydroxybenzene of these were respectively 51. 68 mg/g, 46. 41mg/g.(2) The novel aza-crown ethers chitosan (CTSC) and diaza-crown ether chitosan (CTSDC) were synthesized by the reaction of N-propenyl benzo 15-crown-5 and N, N -dipropenyl dibeno 18-crown-6 with chitosan. Aza-crown ethers crosslinked chitosan (CCTSC) and diaza-crown ether crosslinked chitosan (CCTSDC)were formed by the reation of CTSC and CTSDC with epichlorodydrin under alkaline condition. Their structures were confirmed by infrared spectra analysis, X-ray diffraction analysis. Their adsorption properties for Pd2\ Ag+ were studied, the result shows that adsorption capacities of CTSC (CTSDC) is higher than CCTSC (CCTSDC),and the adsorption selectivities of CCTSC (CCTSDC) is higher than CTSC (CTSDC).