Study On The Preparation Of Polymer Microspheres With Large Specific Surface Area And Their Supporting Properties

As a kind of functional polymer,polymer microspheres have become an important branch of polymer materials.Monodisperse crosslinked polystyrene microspheres,large-size polystyrene microspheres,functional polymer microspheres and so on are the hot research fields of microspheres.The immobilization of?-diimide can solve the problems of deactivation and viscosity in catalytic polymerization.As a good carrier material,polymer microspheres have a very great research and application value.The monodisperse crosslinked polystyrene microspheres have the advantages of very uniform particle size,not easily to be chemically corroded,high mechanical strength,large specific surface area,etc.,and are good carrier materials.In this paper,polystyrene seed particles were prepared by dispersion polymerization,styrene as reaction monomer,divinylbenzene as crosslinking agent,and monodisperse crosslinked polystyrene microspheres were synthesized by Multistep polymerization,and the morphology of the microspheres was characterized by SEM.The effect of polystyrene seed particles addition on microspheres morphology was studied.The results show that the higher the content of polystyrene seed,the smaller the size of the crosslinked polystyrene microspheres,and the more incomplete the microspheres,the more serious the fragmentation,the worse the monodispersity,forming the porous microspheres.Polystyrene seed particles were prepared by soap-free emulsion polymerization.The Polystyrene microspheres with special morphology were synthesized by the modified two-staged seeded swelling polymerization with styrene as the reaction monomer and divinylbenzene as the crosslinking agent,and characterized by SEM.The effect of rotational speed on the surface morphology during polymerization was investigated.When the stirring speed is higher,the particle size of polymer microspheres is smaller,and the regularity of the morphology of the microspheres is worse.The carboxylated polystyrene microspheres with special morphology were prepared by the modified two-staged seeded swelling polymerization and characterized.In the process of polymerization,divinylbenzene and carboxyl functional monomers were used to swell polystyrene seed.The products were characterized by a series of tests.The results show that:(1)the carboxylic monomers were successfully polymerized into the microspheres;(2)the stronger the hydrophilicity of carboxylic monomers,the smaller the specific surface area of the microspheres,and the more irregular the morphology of the microspheres.When the carboxylic monomers were acrylic acid,they could not be polymerized into powder samples,and finally formed a block.(3)when the ratio of polystyrene seed:TBA:DVB=1.5:10:8,the morphology of TBA modified polystyrene microspheres is the most regular,the maximum specific surface area is 9.241m~2/g,and the density of functional groups is the largest.In addition,two kinds of?-diimide catalyst ligands with active groups,L1 with single hydroxyl group and L2 with symmetrical structure of double hydroxyl group,were synthesized.The results show that the catalyst loading rate of t-butyl acrylate modified polystyrene microspheres is higher than that of methacrylic acid modified polystyrene microspheres;the loading rate of L2 is higher than that of L1 under the same microspheres carrier;the loading rate of both L1 and L2 on the two carrier are not high,less than 20%.