| Metal corrosion was worsening in recent years.Polyaniline?PANI?was widely used in anti-corrosion coatings because of its advantage.However,the strong rigidity of molecular chain results poor solubility and processability of PANI.The functional groups exist on the surface of graphene oxide?GO?makes the molecular chains of the polymer can easily adsorbed onto the GO surface,effectively improve the solubility of polymer.Therefore,to form PANI and GO composite material is an effective method to improve the PANI solubility and workability of PANI.In this thesis,cetyltrimethylammonium bromide?CTAB?and cationic gemini surfactant?GS?were used to modify graphene oxide?GO?to prepare a series of modified graphene oxide.Using GO and aniline as raw materials,ammonium persulfate as initiator,CTAB modified GO/PANI?CTGO/PANI?composites and GS modified GO/PANI?GSGO/PANI?composites were prepared.Finally,the compound environmental anticorrosive paint were prepared by using CTGO/PANI and GSGO/PANI composites as fillers,and aqueous alkyd resin?WAR?as matrix.The specific study were as follows:?1?The modified GO was prepared by Hummers method and modified by CTAB and GS,respectively.The structure of modified GO was characterized by infrared?FTIR?and X-ray diffraction?XRD?.The results showed that CTAB and GS were successfully inserted into the GO layers,making the space of GO interlayer in an increase.The scanning electron microscopy?SEM?and atomic force microscopy?AFM?analysis showed that the modified GO layer became thicker and the layers were more looser.When the ratio of GO to CTAB and GS was 1:1,the accumulation of GO was avoided effectively.The results of thermogravimetric analysis showed that the thermostability of CTAB and GS modified GO was significantly higher than that of unmodified GO,and GS modified GO with the best thermal stability..?2?A series of different ratios of polyaniline were prepared by in-situ polymerization of An monomer using APS as initiator.FTIR and SEM results suggested that PANI was prepared successfully.When the ratio of An and APS was1:1 and the reaction time was 12 h,PANI showed obvious rod-like structure and good dispersion.The stability analysis of the dispersion showed that after the prepared polyaniline was allowed to stand for 120 h,the dispersion stability was the best when the ratio of An and APS was 1:1,and it still showed a stable state.Secondly,with An and CTGO,GSGO as raw material and APS as initiator,a series of CTGO/PANI and GSGO/PANI composites were prepared by in-situ polymerization.The results of FTTR,XRD,SEM and TEM showed that the polyaniline was dispersed in the GO layer and formed a sheet-like intercalation structure.The thermal stability of GSGO/PANI composites was better than that of CTGO/PANI composites via their thermal stability analysis.The stability of the composite dispersions showed that the dispersions of CTGO/PANI-2 and GSGO/PANI-2 were stable when the dispersions of CTGO/PANI composites and GSGO/PANI composites were left to stand for 240 h of the dispersed state,no settlement phenomenon.?3?Using CTGO/PANI and GSGO/PANI as filler and WAR as matrix,CTGO/PANI/WAR and GSGO/PANI/WAR anticorrosive coatings were prepared by mechanical blending method.The mechanical properties of the coating show that CTGO/PANI/WAR-2 and GSGO/PANI/WAR-2 with the best mechanical properties.By analyzing the salt spray resistance of the coatings,after 24 h,CTGO/PANI/WAR-2 and GSGO/PANI/WAR-2 showed the best preservative effect.Electrochemical workstation was used to test the electrochemical performance of different coatings.The result showed that the corrosion voltage of CTGO/PANI/WAR-2 was the highest,which was-0.32 V and the corrosion current was the smallest,which was 3.18×10-9 A/cm2.The electrochemical impedance reached 3.65×108?.cm2.The GSGO/PANI/WAR-2 coating had the best corrosion protection in the GSGO/PANI/WAR series and Ecorr increased from-0.56 V in comparison with the WAR coating to-0.28 V,the Icorr decreased from 9.55×10-7A/cm2 to 8.85×10-9 A/cm2,and the electrochemical impedance reached 3.65×108?.cm2.By comparing the CTGO/PANI/WAR-2 and electrochemical analysis of GSGO/PANI/WAR-2 at different etching times showed that the corrosion resistance of CTGO/PANI/WAR-2 and GSGO/PANI/WAR-2 was the best after 24 h corrosion time.Even after 480 hours,immersing impedance electrochemical properties were still superior to pure WAR coating. |
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