Preparation Of Magnetic Modified Graphene Oxide And Research About Barrier Properties Of Epoxy With Aligned Graphene Oxide

Epoxy resin is used for the manufacture of composites tanks due to many excellent properties. However, the small molecules of the gas can diffuse and penetrate in the polymer matrix, and there is a problem that small molecules leak in the composites gas cylinders. Filling flake nanofiller is an effective way to solve this problem. Graphene oxide(GO) is an ideal two-dimensional nano-reinforcements, which can effectively improve the barrier properties of the composites material after aligning in the material matrix. The orientation of fillers can be accomplished under the induction of force field, electric field and magnetic field. Magnetic induction is in situ method, which has no affect on the material matrix and has been widely used for producing composites.The orientation of GO needs high-intensity magnetic field for the poor magnetic response of GO. The complex of GO and magnetic particles was made in recent years. It's a resultful way to reduce the intensity of magnetic field. The magnetic particles combine with the GO under the effect of physical function. Based on the self-polymerization and super-adhesion property of polydopamine (pDOP), the magnetic particles will combine with GO steadily after coated with polydopamine. The consistency of fillers and matrix can be improved too. In view of the above experimental program, the main work is as follows:Magnetic modified GO(GO-Fe3O4-pDOP) was prepared by coprecipit-ation method and coated with polybutamine. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the coating of polydopamine stabilized the combination of Fe3O4 magnetic nanoparticles and graphene oxide. The epoxy composites with random and aligned GO-Fe3O4-pDOP was successfully prepared under lower intensity magnetic field. The barrier properties test showed that the addition and orientation of the magnetic modified graphene improved the barrier properties of the composites. Compared with the pure resin, the water vapor diffusion coefficient <D> of the composites was decreased by 63.7% with the addition of 1.Owt% of GO- Fe3O4-pDOP. With the same content of fillers, the water vapor diffusion coefficient <D> of the composite was decreased by 71.5%after nanofillers aligned. The effect of GO-Fe304-pDOP on the thermal properties of epoxy composites was investigated based on DMTA test. The results showed that with the increasing of the content and the aligning of reinforcements the glass transition temperature (Tg) of composites was improved as well.Based on the two-dimensional flaky structure of graphene oxide, the film consist of oriented GO was prepared by vacuum filtration method. The GO film/epoxy resin composites were prepared. The barrier properties of the composites were tested and analyzed too. The results show that the addition of the GO paper has no effect on the water vapor diffusion coefficient <D> of the composites. But the time required for the diffusion of water molecules to reach equilibrium in the composites is prolonged, and the final weight gain of the composites also increased.