Preparation And Properties Of Graphite And Graphene Oxide/Polymer Composites

Polymer composites play an important role in military and commercial fields.However,there is a common problem of unsatisfactory interfacial bonding effect in polymer composites.Traditional composites can not meet the growing needs of people.Graphene has unique honeycomb structure and excellent physical and chemical properties.It is an ideal inorganic filler.After functionalization treatment,graphene and polymer matrix composite to obtain excellent properties(mechanical,thermal,etc.)has become a research hotspot.The raw material used in this paper is graphite.Firstly,graphite is oxidized,then graphene oxide(GO)is obtained by ultrasonic peeling.Then GO is modified to prepare modified graphene(TPG)/XNBR composite and TPG/epoxy resin composite.The main contents are as follows:(1)GO was grafted with natural tea polyphenols(TP)and TPG was successfully prepared by solution blending.The mechanism of TP grafting GO,i.e.the epoxy ring opening of GO and phenolic hydroxyl dehydration condensation of TP,formed strong intermolecular interaction,was preliminarily discussed.After that,the conditions(ratio,temperature and time)of grafting GO onto TP were changed,and a series of samples were characterized,and the process of grafting modification was further studied.(2)Graphene and Graphite with different particle size and were added to the XNBR matrix to enhance the mechanical,electrical and thermal properties of the rubber.The results show that the tensile strength of rubber composites increases first and then decreases with the increase of graphite content,and the tensile strength of the composites gets a better promotion when GO and TPG are added to the rubber matrix.In addition,the Dynamic thermomechanical analysis showed that the glass transition temperature of XNBR increased from-20.8℃ to-16.5℃ after adding TPG,namely the degree of crosslinking increased significantly.And TPG also had a good effect on the electrical and thermal conductivity of XNBR.(3)TPG/epoxy resin composites were prepared by thermal curing.The thermal stability,mechanical and electrical properties of the composites were studied.In the composites,there is a strong hydrogen bond interaction between TPG and resin matrix,which greatly improves the properties of the composites.When a small amount ofTPG was added,the tensile strength of epoxy resin composites reached 59.85 MPa,which was 13.5% higher than that of pure epoxy resin,and the elongation at break increased by 69.1%.The thermal stability of the composites was improved,and the resistivity of the composites was reduced by five orders of magnitude.