Preparation Of PVC/Graphite Flame Retardant And Antistatic Composite Materials By Solid State Shear Milling (S~3M)

Graphite with special weak interlayer strcture and excellent conductivity property,whichmake it become the common functional types material for polymer/inorganic layerednano-composite preparation, and correspondingly the polymer/graphite nano-compositefunctional type material has attracted more and more attention.According to the graphite easilycaused agglomeration phenomenon and the problems that in the process of polymer/graphitenano-composite preparation.The graphite was organically modified at first, then taking solidshear mill method （S~3M） for preparing partly graphite olefination PVC/graphitenanocomposite, which providing a simple, usful and easy for operation method, and as apossible way for graphene scale production.The experimental results are as follows:1.The structure of the PVC/graphite composite powder prepared by S~3M and thecorrespondingly nano-composite material. The results showed that, under the strongthree-dimensional shear stress field of pan-milling, friction, tensile, dislocation, extrusionchimeric,stretch slipping,shear peeling, grinding,mixed dispersion, realized graphite interlayersplit and nano-composite with polymer.The XRD results indicate that, the graphite half-peakheight and crystallite size are reduced obviously. The TEM showed that, after the treatment ofsolid shear mill, the graphite interlayer splited gradually, some crystal structure is destroyedand completely stripping, realized graphite olefination.The SEM results showed that,PVC/graphite composite powder with lamelliform shape characteristics, and lamellar elongtedwith the increasing milling times, the powder is more fuzziness, length-diameter ratio anddiameter-thickness ratio larger, and the exist independently flake graphite is disappeargradually, which indicate that PVC and graphite embedded each other, and homodisperse, thePVC/graphite composite powder was produced.2.Studied the conductivity of the PVC/graphite composite material.Taking direct hot-press molding and molding after double-roll plastication for the PVC/graphite powder,respectively. The results show that there is a big difference between the two molding methodson conductivity of the PVC/graphite composite material.The surface conductivity reduced5order of magnitude, when the graphite content is2wt%.The volume resistivity reduced5orderof magnitude more, when the graphite content is4wt%.The TEM results show that, thePVC/graphite composite material prepared by S~3M with nano intercalation composite structure,the conductive network is formed through mutual lap among the graphite nano layers, and theagglomeration which is formed through PVC and graphite embedded each other increased thedistribution area.3.Studied the mechanical properties of the PVC/graphite composite material, the resultsindicate that both the processing technology and the organically modified have great effect tothe mechanical properties.When the graphite content is3wt%, the breaking elongation of thecomposite material prepared by S~3M increased more, the breaking elongation of the YEGincreased51.8%, the breaking elongation of the EG increased16.5%. The gap iMPact strengthhas a certain increase, the YEG increased11.8%, the EG increased4%. While the tensilestrength nearly keeps invariant. So, the S~3M technology and organic modify reagent realizedthe toughening effect to the graphite composite.4.The flame retardant of the PVC/graphite composite material is studied, the results showthat S~3M technology has little effect to the oxygen index, but the graphite filling amount hasgreat effect to the oxygen index. Little graphite filling amount could increase the oxygen indexobviously, when the graphite filling amount is2%, the oxygen index increased11.7%, theoxygen index has no obviously change with the graphite filling amount increase.