Preparation And Properties Of Graphene-based Polymer Composites

The effective combination of graphene and polymer materials opens up a new way to prepare new functional composites,and broadens the application fields of polymer materials.The investigation results showed that graphene with excellent comprehensive properties could greatly improve the mechanical properties of polymer materials if it was highly evenly dispersed in polymer materials.At the same time,the addition of graphene could also give polymer materials some special functions,such as conductivity,thermal conductivity and electromagnetic shielding.Therefore,the research on graphene/polymer composites is of great significance,whether from the improvement of the comprehensive properties of polymer materials or the development of new functional composites.In this paper,the research status of graphene-based polymer composites in recent years was summarized and analyzed from the aspects of preparation methods,process routes and main properties.Then,three kinds of modified graphene materials were designed and prepared by three different modification methods,and the modified graphene was used in polymer composites to improve the dispersion effect of graphene in polymer matrix and improve the properties of composites.In the first modification method,the core-shell composite(GO/VP-501)composed of graphene oxide(GO)and carboxylated nitrile rubber microspheres(VP-501)was prepared by hydrogen bond association reaction;in the second modification method,the silane coupling agent KH550 was grafted onto the surface of graphene oxide by dehydration condensation reaction,and then the core-shell composite(rGO-KH550/VP-501)composed of reduced graphene oxide(rGO)and VP-501 was prepared by redox treatment;in the third modification method,the cationic polystyrene particles were prepared by emulsifier free emulsion polymerization and dispersion polymerization.Then,two kinds of reduced graphene oxide/cationic polystyrene composites(rGO/PS,PS uncrosslinked;rGO/JLPS,PS cross-linked.)with pea pod structure were prepared by electrostatic self-assembly.The GO/VP-501/EP composite was prepared by solution blending and mechanical blending.The results showed that when the mass ratio of GO and VP-501 was 1:4,the tensile strength of Go/VP-501/EP composite was 68% higher than that of pure epoxy resin.The rGO-KH550/VP-501/NBR composite was prepared by compounding rGO-KH550/VP-501 core shell composite with(NBR)through emulsion blending and mechanical blending.The results showed that when the mass ratio of rGO-KH550 and VP-501 was 1:7,the tensile strength,elongation at break and shore hardness of the composites increased by 72%,80% and 2.3HA,respectively,and the volume wear decreased by 37.5%.The results also showed that the curing rate index(CRI)increased by78% and the crosslinking density increased by 35%.Two kinds of composites(rGO/PS/NBR and rGO/JLPS/NBR)were prepared by compounding the rGO/PS(rGO/JLPS)with pea pod structure and NBR by means of emulsion blending and mechanical blending.The results showed that the tensile strength of rGO/PS/NBR composites increased by 69% when the filling ratio of rGO/PS was3.0wt%;while the tensile strength of rGO/ JLPS/NBR composites increased by 81% when the content of rGO/JLPS was only 2.0 wt%.At the same time,compared with pure NBR,the CRI of rGO/PS/NBR and rGO/ JLPS/NBR increased by 82% and 111%,the equilibrium swelling degree decreased by 11% and 12%,and the crosslinking density increased by 50% and 58%,respectively.The results indicated that,compared with rGO/PS,rGO/JLPS was more beneficial to improve the properties of composites.