Study On New Method Of Chloromethylation Reaction Of Linear And Crosslinked Polystyrene

1,4-Bis(chloromethoxy)butane (BCMB) was synthesized and its chemical structure and composition of the products were characterized with FTIR and 1H-NMR. The effects of various factors on the reaction were examined, and the reaction mechanism was investigated. The experiment results show that the chloromethylation reagent, 1,4-bis(chloromethoxy) butane, was synthesized easily in a homogeneous system using 1,4-butanediol, formaldehyde and phosphorus trichloride as raw material, and the marked characteristic of the reaction was that the outcome was non-water-solubility. As the reaction carrying out, the outcome separated from the water phase reaction system, what is not only benefit for the reaction progressing, but also convenient to the outcome separating from the system. 1H-NMR results show that the BCMB with great quality was obtained.The chloromethylation of polystyrene (PS) was performed high effectively in a homogeneous system using self made chloromethylation reagent, 1,4-bis(chloromethoxy) butane (BCMB),as the chloromethylation reagent and adopting Lewis acid catalysts. The reaction mechanism was investigated, the effects of various factors on the chloromethylation reaction were examined, and the optimum reaction conditions were determined. The chemical structure and composition of the products were characterized with infrared spectrum and Volhard method. The experiment results show that the reaction mechanism consists of two kinds of reactions possibly, electrophilic substitution on benzene ring and nucleophilic substitution accompanying by ether linkage fission. All the used amount of BCMB, the property and used amount of the catalysts, the property and used amount of solvents and temperature influence distinctly the chloromethylation of polystyrene. There are two types of effects of reaction conditions on the chloromethylation of polystyrene, one is the influence on PS chloromethylation degree, and the other is the influence on remaining linear for PS. The chloromethylated polystyrene with 80% of chloromethylation degree and complete linearity was obtained under the optimum reaction conditions.The chloromethylation reaction of crosslinking polystyrene microspheres (white-sphere) was performed at room temperature using self-made chloromethylation reagent, 1,4-bis (chloromethoxy) butane (BCMB), as the chloromethylation reagent and adopting Lewis acid catalysts, and the chloromethylated crosslinking polystyrene microspheres (chloro-sphere) with a chlorine content of 17% was obtained. The chemical structure and composition of the product were characterized with infrared spectroscopy and Volhard methods, and the effects of various factors on the chloromethylation reaction were examined. The experiment results show that this new method not only is environmentally friendly, but also the reaction is easy to be controlled. Various reaction conditions, such as the reaction time, the species and used amount of solvent, the used amount of catalyst, and the used amount of chloromethylation reagent, will influence the chloromethylation reaction, and the effects of these factors exhibit in two aspects: (1) they affect the chloromethylation degree of the white sphere; (2) they inhibit or accelerate the Friedel-Crafts crosslinking reaction between macromolecular chains and affect the strength of the chloro-sphere. The chloro-sphere with 17% of chlorine content can be prepared when the reaction was carried out at room temperature for 8-10h using CH2Cl2 as solvent and SnCl4 as catalyst.