Study On The Electrical Response Properties Of Polymer@ Barium Titanate Composite Particles

With the development of electronic industry,barium titanate(BT)base materials have become a heated report because of their high dielectric constant,especially applied widely in electro-responsive materials field.But the density of BT itself is big,so it is easy to settlement,what's more,the application properties are severely limited.A lot of work of BT modified had been done by researchers,but in the core-shell structure research aspect,the reports of BT@polymer composite particles have a large proportion,few reports about polymer@BT were reported.Based on the above current situations,the preparation of polymer microsphere has made a series of achievements,for example,narrow size distribution,smooth surface,good dispersion.The methods of polymer@BT composite particles are still at the exploratory stage.The mainly reasons are the difficult to control of smaller particle size,uniformly distribution,excellent crystal phase.Moreover,the nano-sized particles are easy to reunite and difficult to overcome.In this paper,the method of solvent thermal was first introduced to prepare 50 nm BT particle,which show ellipsoid shape,smooth surface and good dispersibility.Based on the previous work,three different kinds of polymer microspheres with similar size were prepared by emulsion polymerization.They are polymethyl methacrylate(PMMA),gelatin(Gel)and chitosan(CS),respectively.Modified the surface of three kinds polymer microspheres by adding silane coupling agent(KH570),results that the reactive groups were grafted.In the condition of acid,polymer and BT were combined by chemical bond.In order to explore the effect of shell content of composite particles and find the optimum electrical response coated content,different shell content of PMMA@BT were made and the structure,morphology and properties have been characterized by SEM,TEM,FT-IR,XRD,CA,TG,Impedance Analyzer and DMA800.According to the optimum ratio of PMMA and BT,Gel@BT and CS@BT composite particles were made.Compare d with the morphology,properties of these three particles,when the content of BT were 58.14%(PMMA@BT),53.87%(Gel@BT),65.23%(CS@BT),the AG%were 21.0%,26.0%and 13.0%,respectively.The result illustrates that the Gel@BT composite particles has the best response performance.This work mainly aims to explore the optimum coated content of polymer@BT and received the expected results.Not only improve the dispersion stability of the composite particle,but explore the influencing factors of composite particles in electrical response.The result provides a effective support of preparing more excellent electrorheological materials.