Preparation And Application Of Halogenated Polymers

Special polystyrene (sPS) prepared by anionic polymerization was brominated by liquid bromine with anhydrous aluminum chloride-aluminum as catalyst in1,2-dichloro ethylene. The product, brominated special polystyrene (BsPS) contains more than60%of bromine. The effect of brominating process, molecular weight, and concentration and bromination time of polystyrene on BsPS was studied in this work. The results show that higher molecular weight and concentration of sPS result in the reduction of the molecular weight of the product (BsPS) significantly during bromination, but has little effect on bromine content of BsPS. Increasing concentration of the sPS solution and shortening bromination time bring on the decrease of the molecular weight and bromine content of BsPS markedly. However, the bromine content of BsPS is more than50%. The blend films of brominated polystyrene and polycarbonate (PC), polyamide (PA-5034) and polybutylene terephthalate (PBT) were prepared by solution blending and spin-coating. Atomic force microscope was used to observe the surface morphology of the blends. Video-based, contact angle measuring device and thermogravimetry (TGA) were used to test the surface energy and thermal performance of the blend films. The results show that reducing molecular weight of sPS or increasing the blend ratio of BsPS in the films can improve the dispersion of BsPS and enhance the surface area of BsPS in PC, PA-5034, and PBT blends, respectively. But the effect of the former is obvious. The hydrophilicity and thermal stability of the blends are increased as well. Chlorinated butyl rubber was brominated by liquid bromine in solution.1H-NMR and gel permeation chromatography (GPC) was used to characterize the brominated chlorinated butyl rubber. Titration method was used to determine the halogen content and unsaturation of the product. The thermal stability of the product was performed on TGA, and the vulcanization of the chlorinated butyl rubber was studied before and after bromination. The results show that the bromine content of brominated and chlorinated butyl rubber is in the range of0.2～0.8%. The saturation of the brominated and chlorinated butyl rubber decreases in some extent, while the thermal stability and vulcanization speed of the chlorinated butyl rubber augment after bromination.