Preparation And Properties Of Brominated Polystyrene

General purpose polystyrene (GPPS) and special polystyrene were brominated by liquid bromine with aluminum chloride-aluminum as catalyst in 1,2-dichlorine ethylene to prepare brominated general purpose polystyrene (BPS) and brominated special polystyrene (BsPS). The effect of bromination time, liquid bromine, catalyst and backbone halogenation suppression additive (BHSA) on bromination of polystyrene were studied in this work. The blend of GPPS/BPS was prepared in solution, and the film was formed by spinning coating, drying and annealing. Atom force microscope was used to observe the morphology of the blend surface. The results show that increase of bromination time results in the increase of the bromine content in BPS, but the marked decrease of the molecular weight of BPS also occurs. BHSA can suppress the occurrence of backbone-breaking in BPS. To increase the addition of the bromine and aluminum chloride arguments the bromine content in BPS, but make the bromination arise along the polystyrene backbone. The enhancement of the bromination temperature causes the decrease of molecular weight of BPS distinctly.1H NMR analysis elucidates that the increases of bromination time, addition of bromine and BHSA are effective to increase the bromine on the benzene ring, and the increases of the catalyst content and bromination temperature decrease the content of bromine on the benzene ring. To increase the concentration of sPS and dropping rate of liquid bromine cause the severe bromination and result in breaking the backbone of sPS, bormination along the main chain of sPS, and decrease of bromine content in BsPS. However, there exists at least a bromine atom on the benzene ring. When brominating, the cleavage of sPS backbone occurs, but is less than that of GPPS backbone. The temperatures of weight loss of BsPSs at 5 wt%are around 340℃, and higher than that of BPS. There are awful compatibility in blends of GPPS/BPS and GPPS/BsPS. The brominated polystyrene is encapsulated by continuous GPPS and dispersed in GPPS even if the blend ration reached at 1:1. The suspension polymerization was used to prepare the blend of PS/BPS. The results indicate that the molecular weight of blends decrease with increase of addition of BPS, and the polydispersity of blends become broad. The thermal analysis of blends show that the glass transition temperature and weight loss of blends augment with increase of the BPS content. The SEM images of the sections of molded blend sheets display that the encapsulated BPS are dispersed in the continuous PS,and the boundary of the incompatible blend of PS and BPS is distinct.