Preparation Of Polystyrene Particles And Their Application In The Field Of Catalytic Degradation

Pesticides play an important role on improving the yield of agricultural products.However,the unreasonable usage of pesticides has result to critical environmental pollution and food security problems.4-nitrophenol is one of the major chemical raw materials for pesticides synthesis,which will result to serious pollution on the environment if not make sewage treatment timely and effectively during pesticide producing process.Some researchers have reported that polymer microspheres material covering with nano silver particles?Ag?can effectively catalytic degraded pesticides and 4-nitrophenol contaminants.Polystyrene particles?PS?are a kind of polymer particles,owning properties of low-cost and easy to be synthesized and modified.Therefore,they are widely applied in many fields.In this paper,we have explored the synthesis and modification methods of PS and have prepared a kind of PS covering with Ag,named PS/Ag.Furthermore,we have evaluated their catalytic performance for 4-nitrophenol and methyl parathion pesticide degradation.Main contents and results are summarized as following:?1?We have synthesized two kinds of uniform sized PS and carboxyl polystyrene particles?CPS?.Results demonstrated that the PS synthesized through suspension polymerization method were non-uniform in size,while the PS prepared by soap-free emulsion polymerization or dispersion polymerization methods were uniform.Hence,CPS were synthesized by soap-free emulsion polymerization method in the following assay.Results indicated that the parameters of initiator and acrylic acid dosage,reaction duration and synthesis temperature could make influence on the morphology of CPS.Moreover,the dosage of acrylic acid would affect the density of carboxyl group on the surface of CPS directly.?2?We have explored a method for magnetic polystyrene particles?MPS?synthesis.The core of MPS,iron??,??oxide?Fe₃O₄?,were prepared by hydrothermal and co-precipitation method.Then,the core Fe₃O₄ was modified by oleic acid,dopamine or?3-Aminopropyl?triethoxysilane?APTES?.Thereafter,the complexs were covered with PS through soap-free emulsion polymerization or dispersion polymerization method.Aminated Fe₃O₄ decorated by dopamine or APTES could combine with acrylic acid and the complexs could be conjugated with styrene to form MPS.Results showed that the morphology of MPS were irregular due to that the aminated Fe₃O₄ were easy to make self-aggregation.However,Fe₃O₄ modified by oleic acid displayed good dispersion.Moreover,the yield of MPS could be effectively improved by adding styrene in beaches or added in crosslinking agent during MPS synthesis.?3?We have prepared a kind of PS/Ag and studied their relative catalytic property for the degradation of 4-nitrophenol and methyl parathion.Results indicated that the PS/Ag synthesized with CPS as carrier owns large size of Ag on its surface.Also,the combination between PS and Ag were relatively weak.However,for the PS/Ag synthesized with dopamine modified PS as carrier,the silver particles loaded on the surface were uniform.Simultaneously,the later PS/Ag presented efficient catalytic degradation effect on 4-nitrophenol and methyl parathion pesticide.