Preparation And Properties Of Graphene Nanoplatelets/Natural Rubber Composites

Rubber is a kind of polymer material with unique high elasticity.At room temperature,the rubber will produce a large amount of deformation with a s mall force acting on the rubber.When the external force is removed,it will quickly return to its original shape.As an important material,rubber has a very long history of use.In recent years,rubber has been used more and more widely in various industries.However,the conventional unreinforced rubber is poor in wear resistance,low in strength,easily oxidized,non-conducting,and not practical.Therefore,most rubbers need to be filled with fillers for reinforcement.Graphene is currently used as a major reinforcing agent for rubber and shows broad application prospects in the rubber industry.However,the single-layer graphene production process is complicated,expensive,and it is difficult to achieve mass production.The graphene nanoplatelets preparation process is simple,inexpensive,and can be mass-produced,and the graphene nanoplatelets can also improve the performance of the rubber as a filler,so it has a great application prospect.In this paper,the preparation process of graphene nanoplatelets/natural rubber nanocomposites was first explored.Firstly,the composite material was prepared by mechanical blending method.The composite material prepared by the method has many micro defects,the surface is rough,the graphene nanoplatelets agglomeration phenomenon is obvious,and the combination of the graphene micro-sheet and the rubber is not very good.The results showed that the tensile strength of the composite material did not have a good regularity,but the elongation at 100%,200%,and 300% of the composite material was improved,containing 10 phr(measurement unit in the rubber system)graphe ne nanoplatelets.At the time of filming,it reached the highest level,which was about 2 times higher than that of pure rubber.Then the graphene nanoplatelets/natural rubber nanocomposite was prepared by latex blending method.The composite material prep ared by using the method has smooth surface and less microscopic defects,the graphene micro-sheet is uniformly dispersed,and the graphene micro-sheet and the rubber interface are combined well.So the performance of the composite material is improved.The results show that the composite material prepared by this method has a tensile strength of 29 MPa when it contains 10 phr of graphene nanoplatelets,increasing 42.5% than that of pure rubber.And the elongation at 100%,200%,and 300% is enhanced by 4 to 8 times that of pure rubber with graphene nanoplatelets increasing in tablet content.The third method is the predispersion method.The composite material prepared by this method also has defects,and the graphene microchip has slight agglomeration phenomenon,so the performance of the composite material is also not very good.The results showed that the tensile strength of the composite material as a whole showed a tendency of increase,which increased by 15.4% when containing 10 phr of graphene nanoplateletsgraphene nanoplatelets.And the elongation at 100%,200%,and 300% is enhanced by 1 times that of pure rubber.C omprehensive comparison of the three methods,latex blending method is simple,the composite material performance is excellent.Although the latex blending method is better than the other two methods,there is still the problem of dispersion of the graphene nanoplatelets.In order to make the dispersion of the graphene nanoplatelets better,the experiment uses polyethylene glycol(PEG)coated type.The method performs physical modification of the graphene flake.The particle size distribution of the modified graphene nanoplatelets was tested,and it was found that the particle size generally increased by 1.7um,indicating that the polyethylene glycol coated the graphene microplate well.The composites were prepared by the latex blending method using the modified graphene nanoplatelets.The results show that the properties of the composites have been correspondingly improved,and the tensile strength can be increased by about 0.5 MPa.The hardness and thermal conductivity of the composites increase gradually with the increase of the content of graphene microchips,which is not relevant to the modification with polyethylene glycol.Finally,in this experiment,a composite material was prepared by the latex blending method,and the electromagnetic shielding performance of the composite material was tested,and a flexible sensor was prepared by a coating method.It was found that the composite material has excellent electromagnetic shie lding performance,and at the same time,it has characteristics such as light ness and flexibility.The results show that the electromagnetic shielding performance of the composite material gradually increases with the increase of the content of the graphene microchip and the thickness of the sample,and the maximum value can reach 80 d B,and the performance is very excellent.For the flexible sensor made of composite material,it also has very good performance.The result shows that the flexible sensor has very good flexibility,and at the same time it has very good sensing performance,and the sensitivity coefficient(K)can reach 171 at most.