Research On Antistatic And Mechanical Properties Of Wood Flour/Poly(Vinyl Chloride) Composites

Wood Flour/Polyvinyl Chloride Composites (WF/PVC) are composed of wood fiber and polyvinyl chloride. Both wood flour and PVC exhibits good electricy insulation. Static electric are easily generated if such composites applied to construction and decorative application, especially applied to workshops of electrical device, computer room and data processing center. It is important to restrain the static electric of WF/PVC composites. Therefore, antistatic electric treatment specific to WF/PVC composites are conducted in this study in order to explore the respective effects of antistatic agent, conductive carbon black (CB) and silane treated conductive CB on electrical resistance, creep resistance and mechanical properties of composites.The study of antistatic performance showed the anionic antistatic agent, conductive CB and CB modified by silane, all could decrease the surface resistivity and volume resistivity of WF/PVC composites to 109 Ω and 109Ω·cm below, displaying differently excellent antistatic properties. When the adding content was up to 20phr, the surface resistivity and volume resistivity of WF/PVC composites decreased form 1016Ω,1015Ωcm to 7.59×105Ω, 7.24×106Ω·cm respectively after adding anionic antistatic agent, while the surface resistivity and volume resistivity of WF/PVC composites decreased to 5.93×107Ω，1.62×106Ω·cm and 5.90×107Ω,1.60×106Ω·cm after adding conductive CB and silane modified conductive CB respectively.Sodium dodecyl sulfate which could knock off ions was the main ingredients of anionic antistatic agent, the long carbon chain of anionic antistatic agent could migrate in PVC resin, both of these reasons caused the composite could conduct electricity. WF/PVC composite showed a phenomenon of "percolation threshold" when the addition amounts of conductive CB and CB processed by silane were up to 14hr, WF/PVC composites displayed a good antistatic properties when conductive CB and modified CB uniformly continuously distributed in a polymer matrix, and a certain distance between adjacent carbon black particles reached.Analysis of mechanical properties showed that the anionic antistatic agent SAS-93 had a certain adverse effect on WF/PVC composites, but conductive CB dealed with silane enhanced the flextural strength and kept a good impact toughness of composites. On the other hand, SAS-93 promoted the deformation of materials based the results of the creep test. However, conductive CB and modifying CB could effectively inhibit the creep deformation of composites.