Preparation Of Divinylbenzene And Glycidyl Methacrylate Copolymerized Coating Carbon Nanotubes And Its Composites And Research On The Dielectric Property

High dielectric nanocomposites have extensive applications as novel electronic materials in various fields such as information,energy,etc.Incorporation of conductive fillers into matrix material successfully prepared composites which have excellent dielectric property.However,how to improve the dispersion of conductive filler in matrix material and enhance the interface interaction of conductive fillers with the matrix material are the key parameters to obtain composites which have excellent property.In this work,we adopt the copolymerized coating method to modify carbon nanotube and introduce reactive epoxy groups on the surface of it,then the epoxy functionalized carbon nanotube we select to compound with resin matrix.Through introducing epoxy group on the surface of CNTs,not only the dispersion of conductive filler in resin matrix material improved and the interface interaction of conductive fillers with the resin matrix material enhanced.The composites which have excellent dielectric property were successfully prepared.The main work was summarized as follows:1.The different coating thickness and the epoxy group on the surface of core-shell structured carbon nanotubes hybrids(DVB-GMA@MWNTs)were prepared by the method of active free radicals initiate divinylbenzene(DVB)and glycidyl methacrylate(GMA)copolymerization at the surface of the carbon nanotube.By adjusting the ratio of the two monomers(DVB:GMA=4:1?1:4),the coating thickness of the CNTs ranging from 5nm to 25nm.At the addition of two monomers(DVB/GMA)is 300/200,the epoxy value on the surface of carbon nanotube is about 0.011 mol/g highest than others.2.The core-shell structured carbon nanotubes hybrids which coating thickness is 25nm,epoxy groups is 0.011 mol/g were selected to compound with epoxy resin to prepare composites.A series of composites(DVB-GMA@MWNTs/Epoxy)with different properties were prepared by changing the addition amount of fillers.Meanwhile,the composites(MWNTs/Epoxy)were prepared by original MWNTs compound with epoxy resin.Compared with the two composites SEM images,the DVB-GMA@MWNTs showed better dispersion in the epoxy resin matrix.As the content of DVB-GMA@MWNTs increase to 30%,the dielectric constant of DVB-GMA@MWNTs/epoxy composites sharply increase to 152 at 10 kHz.Meanwhile,the dielectric loss of the composites is only 0.06.The composites were successfully prepared with high dielectric constant and low dielectric loss.The Polyhedral Oligomeric Silsesquioxane(POSS)matrix with epoxy group was prepared by hydrolytic condensation.The core-shell structured carbon nanotubes hybrids which coating thickness respectively are 25nm and 10nm were selected to compound with POSS to prepare composites.As the content of DVB-GMA@MWNTs which coating thickness is 25nm increase to 20%,the dielectric constant of composites increase to 274 at 1 kHz,the dielectric loss of the composites is only 0.07.As the content of DVB-GMA@MWNTs which coating thickness is 10nm increase to 20%,the dielectric constant of composites increase to 743 at 1 kHz,the dielectric loss of the composites is only 0.7.3.A stable and porous novel composite was successfully prepared by the directly curing method using the hybrids which introduce reactive epoxy groups on the surface of DVB-GMA@MWNTs.The thermal conductivity,dielectric properties of the composites can be controlled by adjusting the addition quality of the two monomers(maintain mass ratio DVB:GMA=3:2)to change the coating layer thickness of the hybrids.