Study On Stabilization And Application Of Ultrafine Negative Ion Powder

The modification of the ultrafine negative ion power was carried out using methyl methacrylate(MMA),which was thickened by polyurethane(PU),as dispersant and Silane coupling agent KH-570 as surface modifier,by means of ball milling.The ultrafine negative ion power slurry was then applied as the dispersed phase to prepare the ultrafine anion power-containing polymeric microspheres,which is the purpose of stabilization of ultrafine negative ion powder.It was conducted in the system involving water as the continuous phase,polyvinyl alcohol(PVA)as the dispersion stabilizer,BPO as the initiator through suspension polymerization.It was found that under the condition of the grinding time at 2 hours,KH-570 concentration at 4% and the solid-liquid ratio at 40:60,it is possible to make it a good surface organic modification.Moreover,with the increasing of the stirring rate in dispersion stage,there is a decrease of the particle size of the microspheres and the coating rate of the anion power.The proper addition of PU gives rise to an increase of the effective content of anion power in the polymeric microsphere.Under the condition of the stirring rate at 550r/min,BPO concentration at 1.4%,PVA concentration at 4.3% and PU proportion at 5.0%,it is possible to obtain the polymeric microsphere with an average particle size of 25?m and good coating rate of the anion powder.The anion coatings was prepared by the modified styrene acrylic emulsion,pigment,filler,negative ion polymer microspheres and various additives.The paper analyzed the effects of the proportion of pigment and filler,the proportion of pigment and polymer,the amount of additives and anion polymer microspheres on the properties of anion coatings.The silicone modified styrene acrylic emulsion was prepared by the addition of KH-570,styrene(ST)and butyl acrylate(BA)and acrylic acid(AA)as the main raw material.This dissertation analyzed the effects of emulsion polymerization process,the amount of acrylic acid,KH-570 dosage,the amount of film forming agent,the glass transition temperature of core and shell on the physical properties of the modified emulsion.It was concluded that under the condition of AA concentration at 2.6g,KH-570 concentration at 3.0g,the glass transition temperature of core and shell at 25.79?and-28.44?,the film forming agent at 2%,it is possible to obtain good performance emulsion by core-shell emulsion polymerization.Moreover,under the condition of the proportion of pigment and filler at 25:75,the proportion of pigment and polymer at 2:2,the dispersant proportion at 1.5%~2%,the anti foaming agent proportion at 0.2%,the thickening agent proportion at 2%,the leveling agent proportion at 2% and the proportion of anion polymer microspheres at 20%,it is possible to prepare fine anion coatings.The anion plastic was prepared by the anion polymer microspheres and polypropylene,though means of melt blending.This dissertation analyzed the dispersion of anion powder and anion polymer microspheres in the PP,the tensile properties,impact properties and anion release under different proportion.It is concluded that the dispersion of anion powder after stabilization in the PP is better than ultrafine anion powder.Besides,the anion plastic is excellent when the proportion of ultrafine anion powder microspheres is 3%.