Study On The Modification Of PVC Calendered Film Matrix

In this paper,PVC composite materials were prepared by mechanical blending.In this process,elastomer,nano-barium sulfate(Nano-BaSO₄)was used as the toughening agent,and carbon black was used as the conductive filler.The mechanical properties of the composite material were tested by tensile and notch impact testing machines,and the surface resistivity of the material was tested by impedance meter.Effects of the type and amount of elastomer,the amount of Nano-BaSO₄,the amount of conductive carbon black and the process conditions on the performance of PVC composites were investigated.During this process,PVC composite materials with good antistatic properties and high toughness were obtained.Through observing the microscopic morphology(SEM),the reasons for changes in mechanical properties were analyzed.The changes about the thermal stability of the composite system were studied by thermogravimetric analysis(TGA).NBR,Polyester TPU,Polyether TPU was selected to modify the toughness of the matrix of PVC calendered film.Through testing the mechanical properties of PVC composites,it was found that with the increase of the content of elastomer,the tensile strength and tear strength of the composite system were decreasing gradually,the elongation at break and impact strength were increasing gradually.Through exploring the mechanical properties of the PVC/NBR/Nano-BaSO₄ composite system,it was found that NBR had a good synergy of toughening with Nano-BaSO₄,and the effect of toughening was the best when the content of NBR was 12phr,and the content of Nano-BaSO₄ was 6phr.In this process,the impact strength?elongation at break of the composite system was 20.67k J/m²?278.42%.Through the analysis of microscopic morphology(SEM),it was found that NBR had good compatibility with PVC;Nano-BaSO₄had poor compatibility with PVC,and the agglomeration phenomenon was appearing when the amount of Nano-BaSO₄ was 6phr.Through the analysis of TG,it was found that NBR can effectively improve the thermal stability of the composite system,but Nano-BaSO₄had little effect on the thermal stability of the composite system.Titanate coupling agent,stearic acid coupling agent and silane coupling agent were used to modify Nano-BaSO₄,and Nano-BaSO₄was characterized by activation degree,contact angle and other properties.It was found that the activation degree and contact angle of Nano-BaSO₄modified by stearic acid coupling agent were the largest,and the effect of modification was the best.Through changing the conditions of modification about the Nano-BaSO₄,it was found that when the temperature of modification was180?,the time of modification was 45min,and the content of modification was 5%,the effect of modification about Nano-BaSO₄ was the best.Through the analysis of Fourier transform infrared spectroscopy(FTIR),it was found that the Nano-BaSO₄surface can be cladded with the titanate and stearic acid coupling agent which showed that the effect of modification was good.The mechanical properties of the PVC/NBR/Nano-BaSO₄ composite system were explored.The results showed that compared with the unmodified system,the mechanical properties of compound system had been significantly improved.When the content of NBR was 12 phr and the content of Nano-BaSO₄ was 8phr,the tensile strength of the PVC composite system was 28.83MPa,the tear strength was 128.04KN/m,the elongation at break was 310.67%,and the impact strength was 28.43k J/m².Through the analysis of microscopic morphology(SEM),it was found that modified Nano-BaSO₄did not coherence,which showed that modified Nano-BaSO₄ had good compatibility with PVC.When the content of Nano-BaSO₄ was8phr,the fibrous drawing was occuring on the impact section of the material,which showed that the toughness of composite system had been improved effectively.Conductive carbon black was used to modify the PVC composite materials,and the effect of the mechanical properties and antistatic properties of composite system with the conductive carbon black were explored.It was found that conductive carbon black can significantly reduce the surface resistivity of the composite system and improve its antistatic performance.With the increasing of the amount of conductive carbon black,the tensile strength was increasing firstly and then decreasing,but the notched impact strength was decreasing gradually.when the amount of carbon black was 15phr,the composite system had good toughness and antistatic performance.In this time,the tensile strength of the composite system was 35.25MPa,the elongation at break was255.42%,and the surface resistivity was 7.33×10⁶?.Through exploring the effect of the process conditions on the mechanical properties and antistatic properties of PVC composites with carbon black,it was determined that the overall performances of the composite system were the best when the mixing time was 12 min and the mixing temperature was 170?.