Design And Preparation Of High Performance PVC/carbon Nanocomposites With Segregated Structure

Firstly,the segregated PVC/RGO nanocomposites（s-PVCG）were prepared by direct hot compression of RGO@PVC.Compared with pure PVC and random PVCG（r-PVCG）,the electrical conductivity,thermal conductivity,thermal stability and flame retardant properties of s-PVCG are significantly improved.The percolation threshold（φ_c）of s-PVCG is as low as 0.012 vol%,and when the RGO content is 2.0wt%,the maximum electrical conductivity of s-PVCG is up to 10^-2S·cm^-1.When the RGO content is 4.1 wt%,the thermal conductivity,maximum thermal weight loss temperature and limiting oxygen index（LOI）of s-PVCG are increased by 75%,21 ^oC and 4^oC,respectively,compared with pure PVC.Secondly,In order to improve the mechanical properties and processing technology of PVC composites,acrylonitrile-butadiene-styrene high rubber powder containing 67 wt%butadiene content（ABS）is chosen as volume exclusion phase and toughening phase for constructing PVC/CCB composites with segregated filler network structure and sea-island phase structure.The volume repulsion of ABS makes the electrical conductivity and thermal conductivity of PVC/ABS/CCB composites increase with the increase of ABS content,and the effective percolation threshold of ABS for the improvement of electrical conductivity and thermal conductivity is 5～8phr and 8～20 phr,respectively.When the CCB content was 5 phr,the conductivity of PVC/ABS/CCB composites with the PVC/ABS ratio of 70/30(10^-11S·cm^-1)was increased by 4 orders of magnitude compared with that of PVC/CCB composites(10^-15S·cm^-1).When the CCB content was 20 phr,the thermal conductivity of PVC/ABS/CCB composites with PVC/ABS a ratio of 70/30(0.121 W·m^-1·K^-1)was52%higher than that of PVC/CCB composites(0.184 W·m^-1·K^-1).When the CCB content was 8 phr,the notch impact strength(24.31 k J·m^-2)of PVC/ABS/CCB composites with PVC/ABS ratio of 70/30 was 107%and 406%higher than that of PVC(11.76 k J·m^-2)and PVC/CCB composites(4.80 k J·m^-2),respectively.In addition,when the content of ABS is less than 20 wt%,the strengthening effect of CCB and the toughening effect of polybutadiene can reach a good match,PVC/ABS/CCB composites can obtain strong and tough mechanical properties.