Study On Preparation, Structures And Properties Of Poly(vinyle Chloride)/graphene Nanocomposite

In recent years, graphene was paid attention in the field of materials because of its outstanding mechanical properties, thermal properties, electrical properties. Melt blending, in situ polymerization and solution mixing were the leading methods to prepare graphene/polymer nanocomposites currently. Melt blending was the most common approach in the industry to prepare graphene/polymer nanocomposites. while, due to its poor dispersity, its application was limited in the field of industrial application of polymer. Poly(vinyl chloride)(PVC) was widely used in many fields as one of five synthetic resins. On the other hand, its application reflected disadvantages in several fields. Therefore, PVC/graphene nanocomposite was studied in this paper to solve dispersity of graphene and improve further properties of PVC. What’s more, preparation, structural properties and feasibility of industrial application of nanocomposite were discussed. Main results are listed below:Graphene oxide was prepared by Hummers method and ultrasonic technique. Then it was reduced by hydrazine hydrate. The results showed that, the graphite was oxidated and lots of oxygen functional groups were implanted successfully. The interlayer of graphene oxide was easier to peel as a result of its bigger interlayer spacing. Meanwhile, graphene oxide could be effectively reduced by hydrazine hydrate.The pre-dispersing XNBR/graphene composite was prepared by latex heterocoagulation, and the dispersity of graphene was investigated by TEM. The effect of p H on Zeta potential of XNBR latex and graphene in aqueous medium has been investigated. The influence of coagulant kinds, temperature, agitation speed and mass ratio between grapheme and XNBRL on hetero-coagulation process were discussed. The results indicated that the Zeta potential of XNBR latex and graphene in aqueous medium were negative, and two particles could not be coagulated in the p H value of 2~10 without the coagulant. Ca Cl2 and Al2(SO4)3 produced preferable effect on the heterocoagulation. The particle diameters decreased with the increase of agitation speed. When the agitation speed reached 300r/min, the smaller and uniform particles could be formed. What’s more, the particle size of coaguated XNBR particles coud be adjusted by the variation of coagulating temperature.PVC/graphene nanocomposite was prepared by melt blending method using XNBR/graphene masterbatch above. Moreover, the effects of graphene on tensile strength, hardness, electrical properties and thermostability of the composite were analyzed. The results showed that the mechanical properties, thermostability and conductivity of the nanocomposite increased obviously. It was found that 0.05% graphene could be well dispersed in PVC matrix, forming a conductive path. With the addition level up to 1%, the electrical conductivity of composite increased from 10-15 S/cm to 10-6 S/cm.The pre-dispersing masterbatch was prepared by latex heterocoagulation, and then nanocomposite was prepared via melt blending method in this paper. Not only could this method improve the mechanical properties, thermal properties, and electrical conductivity, but also, it effectively solved the poor dispersity of graphene. It provided the experimental bases and technology for industrial production and practical applications of graphene in the field of polymer.