Fabrication And Characterization Of Low Content GO/Phenolic Resin Composites

Phenol formaldehyde(PF)has been used in various applications,because of its excellent anticorrosion proterty,flame retardant property,electrical insulation and mechanical property.However,in some special areas such as nuclear-powered ship protective coatings,it is not only required the composite has excellent corrosion protection,but also must posses certain resistance to radiation performance.Therefore,the phenolic resin must be functional modification.Graphene as a new type of two dimensional nanomaterial,has attracted considerable attentions owning to its superior corrosion protection,radiation resistant and mechanical properties.These intrinstic properties have inspired much attention to the fabrication of functional polymer composites to realize its huge potential.In this paper,KH550 and phenol were used to function the graphene oxide(GO)via surface modification.Electrochemical tests and salt spray test were used to research the corrosion protection of the composites under the irradiation envirment.The details are as follows:(1)Firstly,we used the KH550 to modify the surface of GO,and then the KGO/PF composites were prepared by solution blending method.Eventually the GO/PF composites with excellent homogeneous dispersion and interface interaction were obtained.Through SEM and DLS proved that KH550 could improve the interfacial interaction of GO and phenolic,and also furtherly prevent the irreversible agglomerates of the GO in the phenolic resin.The electrochemical test results showed that adding GO could significantly improve the corrosion protection performance of phenolic resin.When the content of GO is 0.2 wt%,the corrosion performance of the GO/PF composites was nearly two times higher than that of pure PF.Besides,With the increasing of irradiation does,the corrosion current density of pure PF increased from 22.71 nA/cm2 before irradiation to 207.7 nA/cm2 at 200 KGy,the corrosion current density increased by nearly eight times.So the ?-irradiation can greatly accelerates the resin's aging which could remarkablely decrease the corrosion resistance of phenolic resin.When the GO content is 0.2 wt%,the corrosion protective performance of the composites is nearly 10 times of pure PF.The electrochemical results indicated that GO could not only improve the corrosion protection performance of phenolic resin,but also could keep the excellent corrosion protection of the phenolic resin under the gamma ray envirment.(2)The GO was modified by simultaneous reduction of phenol,and the GO/PF composites with good dispersibility were prepared by in-suit polymerization.With the help of FTIR and TEM,we study the reduction mechanism between phenol and GO,and the in-suit polymerization mechanism of the GO/PF.The electrochemical test results showed that,the corrosion resistance of phenolic resin could be extremely improved by adding GO.The crosslinking effect of irradiation could promote the cross-linking degree of phenolic resin,and furtherly improve the corrosion resistance of phenolic resin.When the GO content is 0.2 wt%,the corrosion current density is only 1/20 of the pure PF sample.The salt spray test also indicated that GO/PF composites display better corrosion performance than pure PF.(3)With the help of ESR and FTIR,we investigated the degradation mechanism of phenolic resin under the gamma ray.It found that gamma ray could accelerate the oxidation of phenolic resin,and resulting decrease the corrosion resistance.It also furtherly proved that the adding GO could significantly inhibit the oxidation of phenolic resin.The results demonstrated that GO could effectively quench radicals,the GO/PF composites could maintain stable and have a low amplitude attenuation under the gamma irradiation environment.(4)The electrochemical and salt spray test indicated that the GO/PF composites by in situ polymerization displays better corrosion performance than the covalent modification of KGO/PF during the whole irradiation process.So in situ polymerization could be more beneficial to improve the dispersion of graphene in host polymer matrices and furtherly improve the radiation resistance of the phenolic resin.(5)The results of mechanical properties showed that GO could not only improve the toughness of phenolic resin,but also reduce the damage of gamma ray to the mechanical properties of phenolic resin.Therefore,GO/PF composites not only have excellent corrosion resistance,but also have good mechanical property.