Preparation and characterisation of graphene filled unplasticised polyvinyl chloride nanocomposites for mining pipe application

Abstract

This study was aimed to prepare and characterise a graphene filled unplasticised polyvinyl chloride (UPVC) nanocomposite for mining pipe application by means of a conventional dry-blending method. A pre-dispersed reduce graphene oxide (PDG) in Fischer-Tropsch (FT) wax was prepared by defining a melting method with ultrasonic probe. An investigation has been conducted on different types of graphene derivatives: graphene oxide (GO), reduce graphene oxide (rGO) and pre-dispersed rGO (PDG) in Fischer-Tropsch wax (FT wax) filled UPVC nanocomposites. The properties such as electrical, mechanical, rheological and thermal properties were benchmarked against the commercial carbon black (CB) filled UPVC composites for the mining pipe application. The nanocomposites were prepared using the dry-blending method involving different material formulations. The two-roll milling method and the hot press moulding were also employed to produce the test specimens. An environmental friendly stabiliser namely calcium-zinc stabiliser was used to replace the conventional lead stabiliser. The results showed that the specimen with 1.5 phr PDG filled UPVC nanocomposites has the lowest volume resistivity, comparable or higher tensile strength, tensile modulus and impact strength. The specimen was also possessed a wide processing parameter with sufficient heat stability and better cost performance efficiency, compared to the commercial CB filled UPVC composites. The evidences from the fourier transform infrared spectroscopy and scanning electron microscopy images of the surface-fractured specimens showed a well dispersed PDG into the PVC matrix and correlated with the impact strength result. The modulus of the PDG filled UPVC nanocomposites were simulated using the Halpin-Tsai model. The theoretical simulation for the random distribution of PDG supported the results of the experimental data. This study confirmed that the best cost performance of graphene filled UPVC nanocomposites can be achieved by maximising the dispersibility of graphenes within the PVC matrix. This study provides an opportunity for the PDG filled UPVC nanocomposites to be used for mining pipe application.